G7 Q2 (Math)
G7 Q2 (Math)
Mathematics
    Quarter 2 – Module 1:
       Measurements
Mathematics – Grade 7
Quarter 2 – Module 1: Measurements
First Edition, 2020
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
       Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
Mathematics
Quarter 2 – Module 2:
   Measurements
Introductory Message
   4. Observe honesty and integrity in doing the tasks and checking your
      answers.
   5. Finish the task at hand before proceeding to the next.
Let Us Try
Direction: Read the following questions carefully and write the letter of the
correct answer on a separate sheet of paper.
   3. The average newborn weighs about 7 lbs. About how many kg is that?
       a. 2.2           b. 3.2              c. 4.2      d. 5.2
                                        2
   7. What is the most appropriate unit of length for the width of a street?
       a. Millimeter       b. centimeter           c. meter     d. kilometer
                                    1
   8. Which Latin prefix means “      ”?
                                 1000
       a. kilo            b. milli               c. centi            d. deci
   11. What is the most appropriate unit of measure for the distance between
      Davao City and Tagum City ?
       a. millimeter       b. centimeter        c. meter      d. kilometer
   12. Jessica is measuring two line segments. The first line segment is 30cm long.
       The second line segment is 500mm long. How long are the two line segments
       together, in centimeters?
       a. 80 cm           b. 90 cm          c. 50 cm              d. 60 cm
   13. James has 14,500 g of sand in his sandbox. He brings home another 7,400
       g of sand from the beach to add to his sandbox. How many kilograms of sand
       does James have in his sandbox now?
       a. 20.0 kg         b. 21.9 kg           c. 31.9 kg       d. 29.1 kg
   14. A woman’s high jump is 2.1 m, while a man’s high jump is 2.35 m. By how
       many centimeters is the man’s jump higher than that of the woman?
       a. 0.25 cm       b. 2.5 cm           c. 25 cm            d. 250 cm
   15. The smallest mammal, the bumblebee bat, is 1.1 inches long. How long is it
       in centimeters?
       a. 1.794 cm     b. 2.879 cm        c. 2.794 cm          d. 2.974 cm
        Let Us Study
        To understand the lesson let’s have hands-on activities.
Direction: Determine the dimension of the following using only parts of your
arms. Records your results in the table below.
Measurement
                                           3
   ➢ For the arm part, please use any of the following only: the palm, the
     hand span and the forearm length.
Important terms to Remember:
   ➢ forearm length - the length of one’s forearm: the distance from the elbow
     to the tip of the middle finger.
Questions to Ponder:
1. What was your reason for choosing which arm part to use? Why?
   2. Did you experience any difficulty when you were doing the actual
      measuring?
   3. How can you apply your learnings in approximating length in real life
      scenario?
   4. Do you think learning how to approximate length is important? Why
      or why not?
Activity 2:
Direction: Read and understand the concepts to help you to accomplish the
next activities.
Approximating Length
History of Measurement
                                      4
it. Because of this, these units of measurement are called non-standard units
of measurement which later on evolved into what is now the inch, foot, and
yard, basic units of length in the English system of measurement.
Approximating Volume
                                       5
Other common regularly-shaped objects are the different pyramids, the cone,
and the sphere. The volumes of different pyramids depend on the shape of
their base.
      Rectangle-based pyramid:
   Volume =1/3 x length of the base x width of the base x height of pyramid
   (V=1/3 lwh)
Approximating Angle
       Derived from the Latin word angulus, which means corner, an angle is
defined as a figure formed when two rays share a common endpoint called
the vertex. Angles are measured either in degree or radian measures. A
protractor is used to determine the measure of an angle in degrees. In using
the protractor, make sure that the cross bar in the middle of the protractor
is aligned with the vertex and one of the legs of the angle is aligned with one
side of the line passing through the cross bar. The measurement of the angle
is determined by its other leg.
                                      6
Approximating Temperature
                          SYSTEMS OF MEASUREMENT
       Two standard systems of measurement were developed: the US customary or
the “English” system and the metric system. The United States uses the customary
system and some metric, while the rest of the world uses the metric system
exclusively.
                                            7
THE METRIC SYSTEM
    The widely used standard system of measurement is the metric system. It is based
on decimals just like our numeration and monetary systems. Since its introduction
in 1970 by a Frenchman named Gabriel Mouton, the metric system has proven to be
convenient and ideal to use. The system is based on multiples of 10, counting and
performing mathematical operations are easier. It is no surprise then that the metric
system is used in most countries all over the world, including the Philippines.
   The metric system uses Greek and Latin prefixes to make conversion from one
unit to another easier. A prefix is a power-of-10 exponent or multiplier that precedes
the unit. To illustrate what is meant by a prefix, let us take the standard unit for
mass in the metric sytem - the kilogram. In the terms kilogram and milligram, kilo
and milli are the prefixes while gram is the unit.
    The table below shows the Greek and Latin prefixes that are most frequently used
in the metric system.
                                          8
LENGTH
   The most commonly used metric units of length are kilometer (km), meter (m),
centimeter (cm), and millimeter (mm). These units of length are related as follows:
                                       10 mm = 1 cm
                                        100 cm = 1 m
                                       1000 m = 1 km
   One of the advantages of the Metric System, aside from its universality, is that it
uses base 10, which makes conversion from one unit to another much easier.
The result of moving the decimal point to the left is that 8 m = 0.008 km.
                                           9
Example 2. Convert 500 m into cm.
          Beginning at the base unit meter (m), move the decimal point two (2) times
to the right as the unit is converted from larger to a smaller unit. Add two zeros after
the value of 500 to accommodate the two decimal point shifts.
a. 7 cm to mm b. 8 m to cm c. 9000 m to km d. 2.5 m to mm
Solutions:
a. b.
c. d.
                                           10
CONVERSION IN THE ENGLISH SYSTEM
Table of Conversion
                                 12 inches = 1 foot
                                 36 inches = 1 yard
                                 5280 feet = 1 mile
                                 1760 yards= 1 mile
                                 1 inch = 2.54 cm
                                 1 foot = 30.5 cm
                                 1 foot = 0.305 m
                                 1 yard = 3 feet
                                 1 yard = 0.915 m
                                 1 mile = 1.6 km
                                           11
Example 2.
Solutions:
                                        Length
                                     1 in = 2.54 cm
                                     1 ft = 30.48 cm
                                    1 yd = 0.9144 m
                                    1 mi = 1.609 km
                                        Volume
                                     1 gal = 3.785 L
                                         Mass
                                     1 kg = 2.2 lbs
                                     1 oz = 28.35 g
                                          Ares
                                    1 ha = 2.47 acres
                                           12
Example 1: Convert 3 feet to centimeters
Therefore, 3 ft = 91.44 cm
Therefore, 45 kg = 99lbs.
                                            13
MASS/WEIGHT
       Mass and weight are often interchangeably used but their meanings are not
exactly the same. Weight relates to the gravitational pull of the earth upon a mass.
Thus a person’s weight on the moon varies with his weight on Earth. Mass refers to
the amount of matter contained in an object. It remains the same regardless of
location. The standard unit of mass is kilogram (kg), which is the weight of one liter
of water at 4 ͦ C. The gram is of a kilogram. The instruments commonly used to
measure mass are weighing scale and platform balance.
Solutions:
1. 2.
TIME
       The unit of time is second (s). Second is defined as the time occupied by 9
192 631 770 vibrations of the light emitted by a Cesium-133 atom. Time is
introduced with clocks and calendars.
                              UNITS IN TIME MEASURE
Examples
                                         14
Solution:
Temperature
   Temperature refers to the degree of hotness and coldness of a body. The metric
unit of temperature is degree Celsius ( ͦ C). In the Celsius scale, 0 ͦ C is the freezing
point of water, and 100 ͦ C is the boiling point of water. The instrument used for
measuring temperature is the thermometer. Another unit of temperature is degree
Fahrenheit ( ͦ F).
Example: Convert
a. 50 ͦ F to ͦ C b. 40 ͦ C to ͦ F
Solutions:
a. ͦ C = ( ͦF − 32) b. ºF = ͦC + 32
= ( 50 − 32) = ( ) (40) + 32
= ( 18) =(72) + 32
= 10 ͦC = 104 ͦ F
     Area is the surface included within a particular set of dimensions. The basic
unit is square meter (m² or sq. m). A hectare is equivalent to 10 000 m².
                                           15
Example:
                                          16
             SOLVING PROBLEMS INVOLVING MEASUREMENT
Example 1:
       John rode 2 kilometers on his bike. His sister Sally rode 3000 meters on her
bike. Who rode the farthest and how much father did they ride? (answer in
kilometer)
     Solution:
     Convert Sally’s distance to km, 3000m to km. We use the conversion factor
1km= 1000m. We place the old unit, 1000 m , in the denominator and 1 km in the
numerator, since km will be our new unit.
       Sally rode farther because she rode 3km while John only rode 2km. Subtract
their distance covered we arrived with the difference:
Example 2:
                                        17
Example 3:
Example 4:
Example 5:
Let Us Practice
“WHAT AM I?”
                                     18
      Step 1: Give what is being ask in each item.
Questions:
   1. Identify the most reasonable unit to measure the volume of a tumbler.
   2. Which is the closest to the weight of a tomato?
   3. Identify the most reasonable unit to measure the volume of a small
      bottled water.
   4. Identify the most reasonable unit to measure the time it takes to fly
      from Davao to Cebu.
   5. Jeffrey is driving his car. Approximate the amount of time it takes to
      drive from San Pedro Cathedral to Gaisano mall.
   6. Which is the closest to the height of a door?
Answer: _________________________________________________________
c.. 4 kg to cg d. 300 mg to g
e. 62.8 L to mL
                                               19
                                “LET’S CONVERT”
Direction: Convert the following measurements to the indicated units.
      a. 5 ft to inches                          b. 15 ft to yards
e. 5 quarts to pints
                               “COMPUTE ME RIGHT”
Direction: Convert the following measurements to the indicated units up to 2 decimal
places, if possible.
     a. 15 lb = ____kg                           b. 4 gallons = ____L
e. 77 ͦ F = ____ ͦ C
Let Us Remember
   • In converting units in the metric system, we have to follow the rules. First, to
     convert to a smaller unit, multiply by the indicated power of 10. Second, to
     convert to a larger unit, divide by the indicated power of 10.
                                          20
   • To convert English units, you must use a conversion factor. A unit conversion
     factor is a fraction that is equal to 1. The numerator (top) of the fraction
     contains the units of the unit you want to convert to while the denominator
     contains the old unit you want to convert.
       Let Us Assess
Direction: Read the following questions carefully and write the letter of the
correct answer on a separate sheet of paper.
   7. A fully loaded Philippine Air Lines weighs about 320,000 kg. About how many
      tons is that?
      a.. 3.2 tons         b. 32 tons           c. 320 tons        d. 3200 tons
   10. How many milliliters of milk is in the container which says 3.5 L?
      a.. 0.35 ml         b. 3,500 ml           c. 35 ml           d. 350 ml
                                         21
   11. If the length of the stick is 0.572 meter, how long is it in centimeters?
      a. 5.72 cm            b. 57.2 cm           c. 572 cm            d. 5720 cm
   12. John started answering the activities in his module at 8:10 am. He finished
      at 9:25. How many minutes did it take him to finish his work?
      a. 75 min         b. 65 mins            c. 55 mins          d. 1.15 mins
   13. How much heavier is a diamond with a mass of 1.02 g than one that measures
       984 mg ?
       a. 982.98 mg      b. 36 mg            c. 882 mg           d. 985.02 mg
   14. Fourteen milliliters of alcohol is mixed with 4.2 liters of water. How many
      milliliters are there in the mixture?
      a. 4.34 mL             b. 56 mL          c. 4.214 mL          d. 4,214 mL
   15. Kim worked on a computer in the morning for 2 hours and 25 minutes, and
      another 3 hours and 45 minutes in the afternoon. How many minutes did
      she work on the computer on that day?
      a. 370 mins        b. 350 mins        c. 330 mins       d. 300 mins
Let Us Enhance
                               “CHALLENGE ME!”
Complete the table below:
                                         22
                     “LET’S COMPARE AND CONTRAST”
Direction: Complete the graphic organizer “compare and contrast”. Write the
similarities and differences between English System and Metric System.
Let Us Reflect
c. 1 reflection
                                          23
                                        24
                            Let Us Enhance:
                            Challenge Me: Answers may vary
                            Let’s Compare and Contrast!
Let Us Reflect:
        Answers may vary.
Let Us Practice More:       Let Us Assess:                Let Us Try:
“Let’s   Do the Metric”        1.   c                         1.   d
    a.    2,500 cm             2.   a                         2.   b
    b.    6,000 mm             3.   b                         3.   b
    c.    400,000 cg           4.   a                         4.   a
    d.    0.3 g                5.   c                         5.   b
    e.    62,800 ml            6.   d                         6.   c
                               7.   b                         7.   c
“Let’s   Convert”              8.   a                         8.   b
    a.    60 inches            9.   c                         9.   d
    b.    5 yards
                              10.   b                        10.   b
    c.    40 oz
                              11.   b                        11.   d
    d.    5 tons
    e.    10 pts              12.   a                        12.   a
                              13.   b                        13.   b
“Compute Me Right”            14.   d                        14.   c
   a. 6.82 kg                 15.   a                        15.   c
   b. 15.14 L
   c. 43,200 hrs            Let Us Practice:
   d. 20,040 sec            A candle
   e. 25 °C
                                                      Answer Key
          References
Pierce, Rod, "About Math is Fun". Math Is Fun, accessed June 14 2020.
http://www.mathsisfun.com/aboutmathsisfun.html
Pierce, Rod. "Definition of Temperature". Math Is Fun, accessed 14 2020.
June http://www.mathsisfun.com/definitions/temperature.html
Morin, Amanda, “Kid Science: How to Make Your Own Balance Scale”.
ThoughtCo., accessed June 14 2020, https://www.thoughtco.com/kid-
science-make-a-balance- scale-2086574
Learner’s Materials
Retrieved November 2020 from www.purplemath.com
Retrieved November 2020 from https://www.ck12.org/section/convertingmetric-
units-%3A%3Aof%3A%3A-using-dcimals/
                                      25
For inquiries or feedback, please write or call:
Telefax:
                            26
7
    Mathematics
     Quarter 2 – Module 2:
    The Language of Algebra
Mathematics – Grade 7
Quarter 2 – Module 2: The Language of Algebra
First Edition, 2020
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
       Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
Mathematics
 Quarter 2 – Module 2:
The Language of Algebra
Introductory Message
         Let Us Try
Directions: Find out how much you already know about topic. Choose the letter of
the correct answer. Write your answer on a separate sheet of paper.
                                           2
10. Which of the following is the expanded form of 82 ?
     a. 8 + 8                                 c. 8 x 8
     b. 2+2+2+2+2+2+2+2                       d. 8 x 2
12. Which of the following is the mathematical translation of “x less than 8”?
    a. x < 8              b. x > 8             c.   8-x            d. x - 8
14. Which of the following is the mathematical translation of the phrase: “five times
   a number m, increased by 2”?
     a. 5 (m+2)            b. 5m + 2          c. 5 + 2m            d. 5m +2m
          Let Us Study
Algebra is defined as branch of Mathematics which generalizes the facts in
arithmetic. In spoken language, letters and punctuation are used to create words
and phrases. In the language of algebra, letters along with numbers and operation
symbols are used to create expressions. The ability to translate English phrases or
sentences to Mathematical phrases or sentences and vice-versa is an initial step for
us to solve worded problems involving missing quantities.
      A variable is a symbol or letter in the alphabet that may take one or more
than one value from the given replacement set. It represents an unknown value or
number. A variable is written in a small letter. The following are the common symbols
used for variables x, y, z, a, b.
                                           3
variables including the exponents, is/are called literal coefficients. In 5ab², 5 is the
numerical coefficient and ab² is the literal coefficient.
        Similar Terms (Like Terms) are terms which have the same literal
coefficients. -4y² and 7y² are similar terms because their literal coefficients, which is
y², are the same. 5y³ and 10y are not similar because their literal coefficients, which
are y³ and y, are not the same.
       The degree is the highest exponent or the highest sum of exponents of the
variables in a term.
          ➢ For a polynomial with one variable, the degree is the highest exponent
            of that variable.
          ➢ For a polynomial with more than one variable, look at each term and
            add the exponents of each variable in it. The largest sum is the degree
            of the polynomial.
                                           4
Type of Polynomials according to its degree
                 a-7
                  ↑ ↑
          1st term 2nd term
 C            4x2 - 3x + 5             Trinomial – is a polynomial with three terms.
             y3 + 5y -15
     A multinomial is being used to refer polynomials with two or more terms.
                                               5
Some verbal expressions leading to algebraic expressions are shown below.
                           Examples                            Phrases
                                                   the sum of two and a number x
                                                                    or
      Addition                2+x                  the total of two and a number x
                                                                    or
                                                     two increased by a number x
                                                   the difference of twelve and five
                                                                    or
    Subtraction              12 - 5                     twelve decreased by five
                                                                    or
                                                             twelve less five
                                                           thrice a number x
                                                                    or
   Multiplication              3x                   three multiplied to a number x
                                                                    or
                                                  the product of 3 and a number x
                                                 the quotient of a number x and 15
                                                                    or
      Division                x ÷ 15                   a number x divided by 15
                                                                    or
                                                    the ratio of a number x and 15
                                                                  Mathematical
                    English Sentences
                                                                   Sentences
                                         6
  Ten more than a number d is greater than twenty-one.              d + 10 > 21
                                                                       25
 The quotient of twenty-five and a number z is greater                       ≥ 5
                                                                       𝑧
 than or equal to five.
   The product of nine and a number y is less than or
                  equal to thirty-six                                  9y ≤ 36
Let Us Practice
 Directions: Identify the constants, variables, numerical and literal coefficients, and
type of polynomials according to the number of terms.
                                                                             Type of
                                                  Coefficients
                                                                            Polynomial
                                                                            Monomial
 Algebraic                                Numerical      Literal
                  Variable   Constant                                       Binomial
Expressions                               Coefficient    Coefficient
                                                                            Trinomial
3xyz2 + 8
25m² +10n – 6
-5ab²c -8ab – 2
                                          7
                            Activity 2 : “Match Me Up”
                                        8
          Let Us Remember
             +                   -                          ×, ( ) , ·            /,÷
   addition, plus,    subtraction, difference           multiplied,          division, the
 the sum of, more     of, less, decreased by,       multiplied by, product   quotient of ,
  than, increased        subtracted from,            of, twice/thrice a       divided by,
           by,        diminished by, minus,                number               ratio of
    total, added to     reduced, less than
                                                9
Symbols Used for Mathematical Sentences
Symbols Meaning
Let Us Assess
Directions: Choose the letter of the correct answer. Write your answer on the
separate sheet of paper.
                                           10
9. What kind of polynomial is 3(x + 4) ?
    a. monomial          b. binomial            c. trinomial        d. constant
10. What do you call a number or letter that tells the number of times the base is to
    be used as a factor?
     a. constant          b. variable           c. exponent         d. coefficient
13. What is the correct translation of “four subtracted from three times a number
   b”?
     a. 4 - 3b             b. 4b - 4           c. 3b - 4          d. 3 - 4b
Let Us Enhance
Translate the mathematical sentence 2(x-3) = 8 in at least two ways. Use the
different words/phrases that refers to the given sentence.
              1. _____________________________________________________
              2. _____________________________________________________
                                         11
Let Us Reflect
SKILLS ACQUIRED
 Example:
        I can translate verbal phrases to mathematical phrases
 and vice versa.
 One example above is done for you, Now it’s your turn;
    1. _______________________________________________________.
2. _______________________________________________________.
3. _______________________________________________________.
4. _______________________________________________________.
5. _______________________________________________________.
                               12
                             13
                                    Let Us Practice
                                    Activity 2:
                                    “Match Me Up!”
                                            1. E
                                            2. J
                                            3. H
                                            4. D
                                            5. A
                                            6. B
                                            7. C
                                            8. I
                                            9. G
                                           10. F
Let Us Practice                     Let Us   Try
                                        1.    a    11.   d
Activity 1: “Identify Me!”              2.    c    12.   c
                                        3.    b    13.   a
                                        4.    a    14.   b
                                        5.    d    15.   b
                                        6.    d
                                        7.    b
                                        8.    c
                                        9.    a
                                       10.    c
                                  Answer Key
                                          14
Let Us Enhance: (Possible
Answers)
                2(x-3) = 8
   •       Twice the difference of x
           and three is equal to eight.
   •       The product of two and the
           difference of x and three is
           eight.
   •       Two times the difference of
           x and three is equal to
           eight.
Let Us Assess:
 1.    c           11. b
 2.    d           12. a
 3.    a           13. c
 4.    b           14. b
 5.    b           15. d
 6.    d
 7.    a
 8.    b
 9.    a
10.    c
          References
Jisela N. Ulpina and Edna D. Licardo, Math 7 Builders, JO-ES Publishing House,
Inc., 2014, 406 – 415.
                                       15
For inquiries or feedback, please write or call:
Telefax:
                            16
7
    Mathematics
   Quarter 2 – Module 3:
  Evaluation of Algebraic
Expressions, Addition and
Subtraction of Polynomials
Mathematics – Grade 7
Quarter 2 – Module 3: Evaluation of Algebraic Expressions, Addition and Subtraction
of Polynomials
First Edition, 2020
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
       Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
  Mathematics
   Quarter 2 – Module 3:
  Evaluation of Algebraic
Expressions, Addition and
Subtraction of Polynomials
Introductory Message
                                       ii
          Let Us Learn
       Hello learners! Welcome to our lesson for this week which is all about
Evaluation of Algebraic Expressions for given values of the variables (M7AL-IIc-4),
Addition and Subtraction of Polynomials (M7AL-IId-2).
        Specifically, at the end of the lesson, you are expected to:
Let Us Try
Multiple Choice: Choose the letter of the correct answer and write your answer on a
separate sheet of paper.
   1) 3d + 5, where d = 5
      a. -20              b. 20                   c. 15                d. -15
   2) y3 – 8, where y = 4
      a. 56               b. -56                  c. 50                d. -50
        3−𝑥
   4)         , where x = 10 and y = 2.
         4𝑦
        a. -7/8                b. 7/8             c. -8/7              d. 8/7
   5) y2 + x3 + 7, where y = 9 and x = 5
      a. 210               b. 211                 c. 212               d. 213
   2) (4 + 2n3) + (5n3 + 2)
      a. 7n3 + 6                                  c. -7n3 + 6
      b. 7n3 – 6                                  d. -7n3 – 6
                                             1
   3) (a3 – 2a2) – (3a2 – 4a3)
      a. 5a3 + 5a2                              c. 5a3 – 5a2
      b. -5a3 + 5a2                             d. -5a3 – 5a2
Let Us Study
Order of Operations
1. Simplify the expressions inside the grouping symbols, such as braces, parenthesis
or brackets and as indicated by fraction bars.
2. Evaluate all powers and extract roots.
3. Simplify products and quotients in order from left to right.
4. Simplify sums and differences in order from left to right.
Let us try.
                                            2
Evaluate 2x + y if x = -4 and y = 3.
      Solution:
                     2x + y = 2(-4) + 3
                            = -8 + 3
                            = -5
We can represent polynomials using these tiles. Let’s say, 4x2 + x2 can be represented
as,
                                           3
        We also know that, 3x – 4x is represented by getting 3 (+x tiles) and 4 (-x tiles).
Now, let us recall that subtraction also means adding the negative quantity. A pair
of (+x tiles) and (-x tiles) is zero. So, what tiles do we have left? There is 1 (-x tiles)
left. This means that, 3x – 4x = -x.
Let’s consider (2x2 – 5x + 2) + (3x2 + 2x). What tiles would you put together?
        You should have two (+x 2), five (-x) and two (+1) tiles then add three (+x2) and
two (+x) tiles. Matching the pairs that make zero, you have in the end five (+x 2), three
(-x), and two (+1) tiles. The sum is 5x 2 – 3x + 2.
Rules for Adding Polynomials. To add polynomials, simply combine similar terms.
To combine similar terms, get the sum of the numerical coefficients and annex the
same literal coefficients. If there is more than one term, for convenience, write similar
terms in the same column.
              Or        4x2 – 5x + 2
                     + -2x2      +7
                        2x – 5x + 9
                          2
Example 2: The lengths of two ropes are (8x2 + 5x – 2) meters and (2x2 – 9x – 5)
meters. Find the sum of their lengths.
Solution:                   8x2 + 5x – 2
                            2x2 – 9x – 5
                           10x2 – 4x – 7 meters
                                            4
Rules for Subtracting Polynomials. To subtract polynomials, change the sign of the
subtrahend then proceed to the addition rule. Also, remember what subtraction
means. It is adding the negative of the quantity.
Solution:
“Subtract b from a” means a – b. We have,
(6x2 – 7x) – (8x2 + 4x – 3) = (6x2 – 7x) + (-8x2 - 4x + 3)        definition of subtraction
                            = 6x2 - 8x2 - 7x – 4x + 3
                            = -2x2 – 11x + 3
              Or 6x2 – 7x                         6x2 – 7x
                -(8x2 + 4x – 3)                + -8x2 – 4x + 3
                                                 -2x2 – 11x + 3
Example 2: A boy has a stick that is (8x – 3) feet long. Represent the length of the
stick after (2x – 5) feet have been cut off.
Solution:             8x – 3                      8x – 3
                    -(2x – 5)                  + -2x + 5
                                                  6x + 2 feet
Let Us Practice
“The EVALUATION”
                     4𝑥−3
       3. Evaluate          when:
                     3𝑦−4
                     x          -3        -2           -1            0         1
                     y
                                               5
                          “Let’s ADD and SUBTRACT Buddy!”
Directions: Simplify the following polynomials. Match that answer to the correct
letter of the alphabet. Enter that letter of the alphabet on the blank corresponding to
the problem number to find out the secret message.
1. 2x + 3y
2. 10xy + 8xy
3. 20x2 y2 + 30 x2 y2
4. 5x + 3x + 8x + 6x
5. (-5x3) + (-4x3)
6. 10xy - 8xy
7. 20x2 y2 - 30 x2 y2
8. 5x - 3x - 8x - 6x
                                            6
             ___   ___   ___   ___           ___   ___        ___   ___    ___
              5     9     6     2             7    3           4     8      1
Let Us Remember
Let Us Assess
Multiple Choice: Choose the letter of the correct answer and write your answer on a
separate sheet of paper.
   2. b2 + 2b – 3, where b = 11
      a. -140              b. -160                 c. 140                 d. 160
                                             7
      3. -2y2 + x3 + 7, where y = 4 and x = 5
         a. 99                b. -99                       c. 100             d. -100
           12−𝑥
      4.          , when x = 20 and y = 4
            5𝑦
           a. -2/5                 b. -5/2                 c. 2/5             d. 5/2
II. Direction: Read and understand the problem carefully. Complete the table by
               choosing the corresponding letter of your answer from the choices.
       You are walking with your friends at Davao Bolton Bridge. While talking and
chatting with each other, one of your friends accidentally knocked your phone into
the river. Your friend Jaz, a math enthusiast, wants to know the height (in feet) of
your phone above the river at t seconds. So, he calculated it and he found out that
it can be represented by the equation h = -14t2 +1,230. What is the height of your
phone above the river at t = 0, 1, 2, 3, 4? Record your data on the table below.
           t                                            h = - 14t2 + 1, 230
 1.        0           a.   1230        b.   1320                c. 1023              d. 1203
 2.        1           a.   1621        b.   1612                c. 1216              d. 1261
 3.        2           a.   1147        b.   1174                c. 1417              d. 1714
 4.        3           a.   1140        b.   1410                c. 1014              d. 1104
 5.        4           a.   1006        b.   1060                c. 1600              d. 6100
      2. (5x + 4) – (7x + 2)
         a. -2x + 2                             c. 2x + 2
         b. 2x – 2                              d. -2x – 2
                                                    8
   5. Solve: Mark saved 3x2 + 17x – 10 from his allowance. How much did he have
      after buying a gift worth of 12x + 6 for his sister’s birthday?
      a. 3x2 + 5x – 16                   c. 3x2 + 5x + 16
      b. -3x2 + 5x – 16                  d. -3x2 + 5x + 16
Let Us Enhance
x 7x
                                                                            N
                                                  Garlic       xy + 1
   5x        Tomatoes            Okra
W E
4x – 3          Eggplant                         Pechay
                                                               x+5
                                                                            S
5x + 4 x2 – 10 x2 – 6x + 8
                                            9
        Let Us Reflect
On the Heart React, write three things that you have learned about the lesson.
On the Share React, write two real-life situations where you can apply the concept
of algebraic expressions
 ______________________________                   ______________________________
 ______________________________                   ______________________________
 ______________________________                   ______________________________
 ______________________________                   ______________________________
 ______________________________                   ______________________________
 ______________________________                   ______________________________
 ______________________________                   ______________________________
                                       10
                                                        11
Let Us Enhance                                                                  Let us Assess
                                                                                I.
1.   (5x +4) + (x2-10) + (x2-6x+8) or 2x2 - x + 2
2.   x2 + 2x + 8
                                                                                     1.   a
3.   (x2-6x+8) + (x2-6x+8) + (x+5) + (x+5) or                                        2.   c
      2x2 - 10x + 26                                                                 3.   c
4.   (x2-6x+8) + (x2-6x+8) + (xy+1) + (xy+1) or
      2x2 – 12x +2xy + 18
                                                                                     4.   a
                                                                                     5.   d
     Substituting x=3 and y=7. We have
           Perimeter:       2(3)2 – 12(3) +2(3)(7) + 18
                            2(9) - 12(3) + 2(21) + 18                           II.
                            18 - 36 + 42 + 18                                     1.      a
                            42 meters                                             2.      c
                                                                                  3.      b
                                                                                  4.      d
                                                                                  5.      a
                                                                                III.
                                         Let Us Practice                          1.      b
                                                                                  2.      a
                                         The Evaluation
                                                                                  3.      a
                                                                                  4.      c
                                                                                  5.      a
                                                                   c. 48
                                                    1
                                                A.-
                                                    7
Let Us Practice More
                                         Let’s Add and Subtract Buddy!           Let Us Try
                                         I.                                          I.
                                         1.    x + 5y                                     1.   b
                                         2.    14xy                                       2.   a
                                         3.    -8x3                                       3.   c
                                         4.    – 3x – 12                                  4.   a
                                         5.    12x2 + 18xy – 2y2                          5.   d
                                         II.
                                         1.     -7ab                             II.
                                         2.     -12 x2y2                                  1.   d
                                         3.     -12c2d                                    2.   a
                                         4.     - 2x + 2                                  3.   c
                                         5.     - 4a2 – a + 9                             4.   a
                                                                                          5.   d
                                         III.     20x3 – 3x2 – 6
                                                                           Answer Key
          References
                                       12
For inquiries or feedback, please write or call:
Telefax:
                            13
7
    Mathematics
    Quarter 2 – Module 4:
     Laws of Exponents,
Multiplication and Division of
Polynomials, Special Products
Mathematics – Grade 7
Quarter 2 – Module 4: Laws of Exponents, Multiplication and Division of Polynomials
and Special Products
First Edition, 2020
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Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
   Mathematics
     Quarter 2 – Module 4:
       Laws of Exponents,
   Multiplication and Division
Of Polynomials, Special Products
Introductory Message
Let Us Try!
Directions: Find out how much you already know about our lesson. Choose the letter
of the correct answer and write it on a separate sheet of paper.
                                            1
  9. Which of the following states that “in raising a product to a certain power, each
     factor is raised to the indicated power”.
         a. Product of a Power                  c. Quotient of Powers
         b. Power of a Product                  d. Power of a Quotient
  11. What are the Outer Terms if we are to multiply 2x + 3 and x – 4 using the
     FOIL method?
        a. 2x and – 4      b. 3 and x      c. 2x and x        d. 3 and – 4
Let Us Study
                             LAWS OF EXPONENTS
      Exponents follow certain rules that help in simplifying                   exponential
expressions which are also called its laws.
A. Product of a Power
     Consider the following examples:
         1. (x5)(x4) = (x)(x)(x)(x)(x)(x)(x)(x)(x) = x5+4 = x9
         2. (am)(an)         = am+n
         3. 23 22        = (2)(2)(2 )(2)(2) = 23+2 = 25= 32
         4. 10a 10b = 10a+b
         5. (2x3) (3x2) = (2)(3) (x)(x)(x) (x)(x) = 6x3+2 = 6x5
           To multiply two exponents with the same base, you keep the
     base and add the exponents. In symbols, (x a)(xb) = xa+b
                                              2
B. Power of a Power
       Consider the following:
           1. (ax)y     = axy
           2. (x4)2 = x   (4)(2)   = x8
           3. (33)3 = 3(3)(3) = 39 = (3)(3)(3)(3)(3)(3)(3)(3)(3) = 19, 683
           4. (m2)5 = m10
           5. (a2x)y = 22xy
C. Power of a Product
D. Quotient of Power
Examples.
1.   26 = 26-4                 Copy the same base then subtract the exponents. The
     24                        exponent of the numerator is greater than the exponent
        = 22                   of the denominator.
        =4                     Simplify.
2. 18 x4 y5 z3 = (6•3) x4-2 y       5-2   z3-1           Get the factors. Cancel common factors
   24 x2 y2 z    (6•4)
                                                          3
3. b5     = b5-3 = b2                        Copy the same base then subtract the exponents.
   b3
                                      xa = 1               If a < b and x ≠ 0
                                      xb xa-b
                                      xa = xa-b = x0 = 1   If a = b, and x ≠ 0
                                      xb
D. Power of a Quotient
             1.         x       4    = x4
                        y              y4
             2.     3x          2     = (32)(x2) = 9x2
                    2y                  (22)(y2)   4y2
             4.     2       2   = 22         = 4
                    3             32           9
             5.     x2      2       = x2(2) = x4
                    5                 52      25
                                                      4
       MULTIPLICATION AND DIVISION OF POLYNOMIALS
   2.) 9y (5y3 – 3y + 5)
      Solution:
       9y (5y3 – 3y + 5) = 9y (5y3) + 9y (– 3y) + 9y (5)
                           = 45y4 – 27y2 + 45y
                                           5
      2. (8x2 + 7x – 11) (2x – 3)
                     8x2 + 7x – 11
                           2x – 3
                  -24x2 – 21x + 33                  Multiply 8x2 + 7x – 11 by -3
            16x3 +14x2 – 22x                        Multiply 8x2 + 7x – 11 by 2x
            16x3 – 10x2 – 43x + 33                  Align like terms, then add.
Horizontal Form
      1. (4x – 4) (2x + 5)
            Multiply each term of the first polynomial to each term of the second
      polynomial. Combine like terms
         (4x – 4) (2x + 5) = (4x) (2x + 5) + (-4) (2x + 5)
                             = (4x) (2x) + (4x) (5) + (-4) (2x) + (-4) (5)
                             = 8x2 + 20x – 8x – 20
                             = 8x2 + 12x – 20       (final product)
Examples:
      1. Divide (4x8 – 4x4 + 8x3) by (2x2)
      Solution:
      Step 1: Rewrite the problem. Write each term in the polynomial as dividend
      of the monomial.
                                              6
      Step 2: Follow the laws of exponents and operations on integers and divide
      each term by the monomial. Therefore,
       In finding the quotient of two polynomials, use the same procedure in doing
ordinary division with whole numbers. Make sure that both the dividend and the
divisor are in the standard form. It guarantees that their exponents are in decreasing
order from left to right. Also, insert zero(s) for missing terms.
Examples:
      1. (6x2 -2x – 28) ÷ (2x + 4)
      Solution:
      Step 1: Divide the leading term of the dividend by the leading term of the
      divisor.
      Step 2: Place the partial quotient on top.
      Step 3: Now take the partial quotient you placed on top, 3x, and distribute
      into the divisor (2x + 4).
      Step 4: Position the product of (3x) and (2x + 4) under the dividend. Make
      sure to align them by similar terms.
                                          7
Step 5: Perform subtraction by switching the signs of the bottom polynomial.
Step 6: Proceed with regular addition vertically. Notice that the first column
        from the left cancels each other out.
Step 7: Carry down the next adjacent “unused” term of the dividend.
Step 8: Next, look at the bottom polynomial, −14x − 28, take its leading term
        which is −14x and divide it by the leading term of the divisor, 2x.
Step 10: Use the partial quotient that you put up, −7, and distribute into the
         divisor.
                                   8
       Step 11: Place the product of −7 and the divisor below as the last line of
                polynomial entry.
Step 12: Subtraction means you will switch the signs (in red).
Step 13: Perform regular addition along the columns of similar terms
       Step 14: This is great because the remainder is zero. It means the divisor is a
                factor of the dividend. The final answer is just the expression on
                top of the division symbol.
                   Therefore, the quotient is 3x – 7.
2. Divide:
       Solution:
       Step 1: Divide the leading term of the dividend by the leading term of the
               divisor.
       Step 2: Place the partial quotient on top.
                                             9
Step 3: Now take the partial quotient you placed on top, x 2, and distribute
        into the divisor (x + 2).
Step 4: Position the product of (x2) and (x + 2) under the dividend.
Step 6: Proceed with regular addition vertically. Notice that the first column
        from the left cancels each other out.
Step 7: Carry down the next adjacent “unused” term of the dividend.
Step 8: Next, look at the bottom polynomial, −6x2 + 2x, take its leading term
        which is −6x2 and divide it by the leading term of the divisor, x.
Step 9: Again, place the partial quotient on top.
Step 10: Use the partial quotient that you put up, −6x, and distribute into the
         divisor.
Step 11: Place the product of −6x and the divisor below as the last line of
         polynomial entry.
Step 13: Perform regular addition along the columns of similar terms. Bring
         down the next term.
                                   10
Step 14: Repeat the same process. Divide the leading term of the bottom
         polynomial by the leading term of the divisor. In this case, we have
         14x divided by x which is +14.
Step 15: Multiply (or distribute) the answer obtained in the previous step by
         the polynomial in front of the division symbol. In this case, we need
         to multiply 14 and (x + 2).
Step 16: Subtract and notice there are no more terms to bring down.
Step 17: Write the final answer. The term remaining after the last subtraction
         step is the remainder and must be written as a fraction in the final
         answer.
                                  11
                              SPECIAL PRODUCTS
        Multiplying two polynomials together, if they have more than three terms and
 in their terms have several variables, can be very tedious and you will take a lot of
 time to finish.
       Would you like to know how to identify when you have a special product and
 how to apply its formula?
       In this module it will be explained to you, step-by-step, the different special
 product formulas. Examples were answered so that you will learn how to apply them
 in your exercises.
                                          12
Example 2: Illustrate the product of (x + 1)(x - 2) using algebra tiles.
Using the concept of Algebra tiles, observe the figure below. Given (a + b) (c + d),
       To get the total area of the rectangle, we simply add ac + bc + ad + bd. This
is the general form of multiplying two binomials: (a + b)(c + d) = ac + bc + ad + bd.
This form is also known as the FOIL Method.
                                            13
Example 1: Multiply: (5x – 3) (2x + 7)
      The product of the sum of two terms (a + b) and the difference of the same
terms (a – b) is the difference of the squares of the two terms.
                                         Example
       Problem             Multiply the binomials. (2n – 5)(2n + 5)
                                           14
     More Examples:
                1. (x + y )(x – y) = x2 – y2
                2. (2c + 3)(2c – 3) = 4c2 – 9
                3. (m + n)(m – n) = m2 – n2
                4. (3x – y)(3x + y) = 9x2 – y2
                5. (6p – 2r)(6p + 2r) = 36p2 – 4r2
                                       Example
Problem                         Square the binomial. (2x +6)2
More Examples:
                1. (a + 1)2 = a2 + 2a + 1
                2. (y + 3)2 = y2 + 6y + 9
                3. (2a + 4)2 = 4a2 + 16a + 16
                4. (3x + 5)2 = 9x2 + 30x + 25
                5. (7m + 6n)2 = 49m2 + 84mn + 36n2
                                            15
  Case 2. Squaring a Binomial Difference
          To square a binomial difference, do the following:
                ➢ Square the first term
                ➢ Subtract the product of the two terms, times two
                ➢ Add the square of the last term.
                                               Example
      Problem                          Square the binomial. (x – 7)2
                               (x)2 Square the first term.
                  (x)(-7)(2) = -14x Multiply the two terms together and double the
                                    product.
                        (-7)2 = 49 Square the last term.
                   x2 – 14x + 49 Combine the like terms.
                       Answer       (x – 7)2 = x2 – 14x + 49
More Examples:
                   1. (k - 1)2 = k2 – 2k + 1
                   2. (t - 8)2 = t2 – 16t + 64
                   3. (6h - 3)2 = 36h2 – 36h + 9
                   4. (2x - 10)2 = 4x2 – 40x + 100
                   5. (2m - 7n)2 = 4m2 – 28mn + 49n2
                                                 16
     Examples:
     1. (x + y)3 = (x)3 + 3(x)2(y) + 3(x)(y)2 + (y)3 = x3 + 3x2y + 3xy2 + y3
     2. (x + 4)3 = (x)3 + 3(x)2(4) + 3(x)(4)2 + (4)3 = x3 + 12x2 + 48x + 64
     3. (2b + 3c)3 = (2b)3 + 3(2b)2(3c) + 3(2b)(3c)2 + (3c)3 = 8b3 + 36b2c + 54bc2 + 27c3
     Examples:
            1. (x2 – xy + y2)(x + y) = x3 + y3
            2. (m2 + mn + n2)(m - n) = m3 – n3
            3. (f2 – fg + g2)(f + g) = f3 + g3
            4. (x2 - 4x + 16)(x + 4) = x3 + 64
            5. (y2 + 5y + 25)(y – 5) = y3 – 125
            6. (4x2 – 6x + 9)(2x + 3) = 8x3 + 27
         Notice that the product is always the sum or difference of two cubes. This
 method is only applicable if the given binomial and trinomial follows the general form,
 that is, if you square the first term of the binomial you will get the first term of the
 trinomial; if you multiply the first and second term of the binomial you will get the
 second term of the trinomial; and if you square the second term of the binomial you
 will get the last term of the trinomial. Take note also of their signs.
                                                 17
            Let Us Practice
 I.   Identify the law of exponent and simplify the following expressions. Write your
      answers on the space provided before the number.
__________________________________ 1) (a 2bc) 3
__________________________________ 2) 4xy2 3
3wz
__________________________________ 3) m 5 ∙ m3
__________________________________ 4) (32)4
      __________________________________ 5) x -9 y3
                                            X -7 y8
II.   Match given pairs of polynomial in column A with the correct product or
      quotient in column B. Write the letter of your answer on the space provided
      before the number.
A B
_____ 1) 2 (x + y) a. y2 – 2y + 3
      _____ 3) (a2 + 2a – 4) (a – 3)           c. 2x + 2y
      _____ 4) 10y3 – 20y2 + 30y               d. x - 5
                      10y
      _____ 5) x2 ─ 3x ─ 10                    e. a3 – a2 – 10a + 12
                   x+2
 I.   Find the product using the FOIL method. Write your answers on the spaces
      provided:
      1.   (x   + 2) (x + 7)            _______________________________________
      2.   (x   + 4) (x – 8)            _______________________________________
      3.   (x   – 2) (x – 4)            _______________________________________
      4.   (x   – 5) (x + 1)            _______________________________________
      5. (2x + 3) (x + 5)               ____________________________________
                                         18
 II.   State the type of special product to be used in solving the following pair of
       polynomials the easiest way. Write only the corresponding letter on the
       space before each item.
Let Us Remember
Laws of Exponents
                                    xa = 1               If a < b and x ≠ 0
                                    xb xa-b
                                    xa = xa-b = x0 = 1   If a = b, and x ≠ 0
                                    xb
   5. Power of a Quotient           𝑥   a   = xa
                                    𝑦         𝑦a         where y ≠ 0
                                             19
Multiplication and Division of Polynomials
      In multiplying a polynomial by a monomial, multiply each term. The Laws of
Exponents and the Distributive Property of Multiplication over Addition or
Subtraction can be used.
       In multiplying a polynomial by a polynomial, take one term of the multiplier
and multiply the multiplicand at a time. See to it that the similar terms must fall on
the same column in writing partial product, then combine similar terms to express
the product in simplest form.
      To divide a polynomial by a monomial, divide each term of the polynomial by
the monomial. The law of exponents for division is applied in simplifying the powers
appearing in each term.
      To divide a polynomial by a polynomial, use the same procedure in doing
ordinary division with whole numbers.
Special Products
   3. Square of a Binomial
                   (a + b)2 = a2 + 2ab + b2
                   (a – b)2 = a2 – 2ab + b2
   4. Cube of a Binomial
                   (a + b)3 = a3 + 3a2b + 3ab2 + b3
                   (a – b)3 = a3 – 3a2b + 3ab2 – b3
                                         20
        Let Us Assess
MULTIPLE CHOICE: Find out how much you already know about our lesson. Choose
the letter of the correct answer and write it on a separate sheet of paper.
   2. What law of exponent will satisfy the given equation: (m2)(m3) = m5?
        a. Power of powers                     c. Quotient of a Power
        b. Product of a Power                  d. Law for Zero Exponent
   11. In multiplying binomials (9x – 2)(x + 5) using FOIL method. Which terms
       should be multiplied first?
         a. (9x)(x)      b. (9x)(5)            c. (x)(-2)        d. (-2)(5)
                                             21
            b. 49x2 + 9y2                                  d. 49x2 + 42x + 9y2
     13. What is the last term of the product of (7x + 4) and (7x – 4) ?
          a. -8              b. -16              c. -28               d. 0
Let Us Enhance
                                          “Who Is He?”
The letters will form a name of a great mathematician. He was the first Greek
mathematician who recognized fractions as numbers; thus, he allowed positive
rational numbers for the coefficients and solutions. He was also the author of a series
of books called Arithmetica.
To find out the answer, simplify and write the letter corresponding to the answer in
the boxes below.
                                                  22
       Let Us Reflect
Complete the reaction boxes by stating the concepts you have understood in this
module under ACCOMPLISHMENTS and writing the things that still confuse you
about the lesson under CHALLENGES.
                                      23
                                              24
Let Us Enhance
Let Us Assess                                      Let Us Practice More
    1.   b        11.   a                             I.    1.   x2 + 9x + 14
    2.   b        12.   c                                   2.   x2 – 4x – 32
    3.   c        13.   b                                   3.   x2 – 6x + 8
    4.   d        14.   d                                   4.   x2 – 4x – 5
    5.   a        15.   A                                   5.   2x2 + 13x + 15
    6.   c
    7.   b                                            II.   1.   E   6. B
    8.   a                                                  2.   A   7. E
    9.   a                                                  3.   D   8. A
   10.   c                                                  4.   C   9. B
                                                            5.   D   10. D
Let Us Practice                                    Let Us Try
   I.    1. Power of a Product    a6b3c3               1. b
                                                       2. a
                                  64𝑥 3 𝑦 6            3. c
         2. Power of a Quotient
                                  27𝑤 3 𝑧 3
                                                       4. d
         3. Product of a Power    m8                   5. b
                                                       6. b
         4. Power of a Power      6,561
                                                       7. c
                                   1
         5. Quotient of a Power                        8. d
                                  𝑥2𝑦5
                                                       9. b
   II.   1.   c                                        10. a
         2.   b                                        11. a
         3.   e                                        12. c
         4.   a                                        13. b
         5.   d                                        14. d
                                                       15. b
                                                                 Answer Key
         References
https://www.mesacc.edu/~scotz47781/mat120/notes/polynomials/foil_method/f
       oil_method.html
http://www.montereyinstitute.org/courses/DevelopmentalMath/COURSE_TEXT2_
       RESOURCE/U11_L2_T4_text_final.html
https://www.math-only-math.com/cube-of-a-binomial.html
https://brainly.ph/question/683476
https://courses.lumenlearning.com/prealgebra/chapter/multiplying-a-trinomial-
       by-a-binomial/
https://mathbitsnotebook.com/Algebra1/Polynomials/POpolynomial.html
Elizabeth R. Aseron et. Al, Mathematics 7 Learner’s Material: Pasig City: DepEd
       IMCS, 2013, 153-161
                                      25
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Telefax:
                            26
 7
     Mathematics
     Quarter 2 – Module 5:
Algebraic Expressions, Equations
        and Inequalities
Mathematics – Grade 7
Quarter 2 – Module 5: Algebraic Expressions, Equations and Inequalities
First Edition, 2020
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
       Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
     Mathematics
     Quarter 2 – Module 5:
Algebraic Expressions, Equations
        and Inequalities
Introductory Message
For the facilitator:
      As a facilitator, you are expected to orient the learners on how to use
this module. You also need to keep track of the learners' progress while
allowing them to manage their own learning at home. Furthermore, you are
expected to encourage and assist the learners as they do the tasks included
in the module.
                                       ii
         Let Us Learn
       Let Us Try
Directions: Find out how much you already know about this module. Choose the
letter of the correct answer. Write your answer on a separate sheet of paper.
   1. In a bowl of fruits, there are a mangoes and b papayas. In a paper bag, there
      are 5 mangoes and 9 papayas. Write the total number of fruits as an
      expression.
      A. a + b + 5          B. a + b + 14      C. a + b + 9       D. a + b – 14
   2. Mary has 50 mangoes. If she sells x mangoes per day for 7 days, how many
      mangoes will he have left? Write an expression.
      A. 7x - 50         B. 7x + 50           C. 50 - 7x        D. 50 + 7x
   3. Find the perimeter of an isosceles triangle whose two legs has the measurement
       of x + 3 and the base is x.
       A. 3x + 6            B. x + 6             C. 6 +3x             D. 6 + x
   4. Ann is m years old. John is five years younger than Ann. How old will John
      be in 10 years?
      A. m + 5            B. m – 5            C. m + 10         D. m - 10
    5. Johnny takes h hours and m minutes to complete the typing job. His friend
       Andrew takes as twice as long to finish typing. Write an algebraic expression
       for Andrew’s typing speed.
       A. 2 hm             B. h + 2m           C. 2h + m           D. 2h + 2m
    6. Angeline has 80 more pesos than Lily has. If c equals the amount of money
       Lily has, which of the following expressions represents the amount Angeline
       has?
       A. 80c              B. 80 - c            C. c +80           D. c- 80
                                          3
    9. Which of the following is not an example of linear equations?
       A. 2x + 10 = 30     B. 5(x- 8) = 60     C. y + 35 ≠ 10      D. 4x - 5 = 11
   15. Which of the following statements describes a linear equation in one variable?
       A. It has one or more algebraic terms in a phrase.
       B. It has a definite solution.
       C. It has more than one solution.
       D. There is “>” sign.
Let Us Study
  1. Read the problem carefully. You may not be able to visualize all the details,
     but you should gain a mental picture of what is generally being discussed.
  2. Determine what the problem is asking for. A problem may provide you with
     enough details to calculate all sorts of parameters, but the problem probably
     will only be asking for one or two. Thus, figure out what you are trying to find
     and write it down.
                                          4
3. Identify the variables. As you have learned from the previous lesson, the
   variables are symbols or letters in the alphabet. Use this to represent the
   missing quantity.
4. Translate the problem into a mathematical expression. In order to solve the
   expression, you have to translate from verbal phrases/sentence into a
   mathematical expression.
5. Solve the problem and check your results. You can now solve the given
   expression and make sure to check thoroughly the result or answer.
EXAMPLES:
                                         5
                    Let c – the number of chocolates and d – number of drinks
                    Ethan snacks
                    c-5     Ethan has five fewer chocolates than Beverly
                    2d      and twice as many drinks
EQUATION
        An identity equation is true for all values of the variable. Here is an example
of an identity equation.
                                     5x = 4x + x
The solution set consists of all values that make the equation true. For this equation,
the solution set is all real numbers because any real number substituted for x will
make the equation true.
                                          6
     A conditional equation is true for only some values of the variable. For
example, if we are to solve the equation 4x + 2 = 3x - 1, we will arrive with:
4x + 2 = 3x – 1
4x - 3x = -1 - 2
x=-3
The solution set consists of one number : {-3}. It is the only solution and, therefore,
we have solved a conditional equation.
3x - 15 = 3x - 4
INEQUALITY
x ≥ 20 2n + 5 > 33 x - 7 < 24 y + 3 ≤ 25
                                            7
                                  • It uses an equal sign (=) as •     It uses an
•     It only has operating
                                    relation symbol.                   inequality sign (<,
      symbols and no
      relation symbols.                                                ≤, >, ≥) as
                                                                       relation symbol.
Let Us Practice
          a+b+c=0                54x                       -x + 2 = 18
          8x +5                  c – 1 > -4                y > 15
          -y+ 7                  x≤5                       x = -5
          3+m<2                  2x + 6 = 24               6(n + 8 )
          x+y+z                  5 – b ≤ -4                6(3) + 1 = x
                                                8
   Activity 2: “Identity, Conditional or Inconsistent Equation?”
   A. Direction: Determine whether the given equation is identity, conditional or
      inconsistent linear equation. Write your answer on the space provided before
      the number.
_________2. 2x + 1 = 2x - 8 ________7. x + 1 = -3
Let Us Remember
                                         9
   3. An equation uses an equal sign “=” while an inequality uses symbols such as
      <, ≤,>, ≥ and ≠.
   4. A linear equation in one variable is one which can be written in the form ax +
      b = 0, where a and b are real numbers and a ≠ 0. It has three types: identity,
      conditional and inconsistent.
Let Us Assess
Directions: Choose the letter of the correct answer. Write your answer on the separate
sheet of paper.
   3. In a box, there are x white chocolates and y dark chocolates. In another box,
      there are 5 white chocolates and 7 dark chocolates. What is the total number
      pieces of chocolates combined?
      A. x + 12            B. y + 12           C. 5x +0           D. x + y + 12
   5. It uses an equal sign (=) as relation symbol that shows equality between two
      expressions.
      A. Equation         B. Expression        C. Inequality     D. Equivalent
   6. Emelio takes h hours and m minutes to complete a mini- triathlon. His friend
      Aguinaldo takes thrice as long to finish the race. Write and algebraic
      expression for Aguinaldo’s race time.
      A.3 hm              B. 3h + 3m        C. 3h + m           D. h + 3m
   8. Adrian has r red marbles and b blue marbles. Mark keeps losing his marble,
      and has half as many red marbles, and 5 less blue marbles than Adrian. Write
      an expression for Mark’s total marbles.
         2                  𝑟                    𝑟                   𝑏
      A. + b -5          B. + b +5            C. + b -5           D . + r -5
          𝑟                  2                     2                   2
                                         10
   10. Which inequality symbol means “less than or equal to”?
       A. <              B. ≤               C. >                    D. ≥
   12. Which of the following is a statement in which two expressions, at least one
       containing the variable, are equal.
       A. Equation        B. Inequality       C. Expression      D. Equivalent
   13. Sheila is eight years older than her brother. If her brother is m years old,
       how old is Sheila five years ago?
       A. m + 3           B. m – 3            C. m + 13           D. m – 13
Let Us Enhance
Write at least five verbal statements about your relationships with your classmates,
friends or parents. Translate them into mathematical statements.
              1. _________________________________________________________.
              2. _________________________________________________________.
3. _________________________________________________________.
              4. _________________________________________________________.
              5. _________________________________________________________.
         Let Us Reflect
  Comment on this statement:
                                         11
              Answer Key
                C       10.
                C        9.
                C        8.
                A        7.
                C        6.
    B   15.     D        5.
    D   14.     A        4.
    C   13.     A        3.
    D   12.     C        2.
    A   11.     B        1.
               Try   Let Us                                  Let Us Practice: Activity 1
          Conditional    10.
          Inconsistent    9.
          Inconsistent    8.                                        B           10.
          Conditional     7.           35x - 40     5.              B            9.
          Identity        6.                                        C            8.
                                               𝑏
          Conditional     5.              +5        4.              C            7.
                                               70
          Identity        4.                                        B            6.
          Identity        3.       1000 + 500n      3.   D    15.   A            5.
          Inconsistent    2.        6x + 2x = 8x    2.   B    14.   D            4.
          Identity        1.                             A    13.   D            3.
                                               4x   1.   A    12.   D            2.
          Activity 2                                     C    11.   C            1.
          Let Us Practice:     Let Us Practice More                 Us Assess    Let
References
                                          12
For inquiries or feedback, please write or call:
Telefax:
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
the Government of the Philippines. However, prior approval of the government agency or office
wherein the work is created shall be necessary for exploitation of such work for profit. Such
agency or office may, among other things, impose as a condition the payment of royalties.
       Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this module are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
  Mathematics
    Quarter 2 – Module 6:
Solving Linear Equations and
 Inequalities in One Variable
Introductory Message
                                       ii
          Let Us Learn
          After going through this module, you are expected to:
Let Us Try!
MULTIPLE CHOICE: Read and understand each question carefully. Then, write the
letter of your answer on a separate sheet of paper.
   3. Given the replacement (- 20, - 8 , 0, 8, 20), which of the following is/are the
      solution/s of the equation – ½ x + 7 = 3?
         a. 8                    b. - 8                c. 20                 d. - 20
   4. Given the replacement set ( - 2, -1, 0, 1, 2, 3), which of the following is/are
      the solution/s of the inequality 3x - 1 > 2?
         a. x = (-3, -1, 0, 2)                          c. x = (2, 3)
         b. b. x = (0, 1, 2, 3)                         d. x = ( -2,-1, 0)
   5. Consider this statement: “If milk + tea = milk tea, then milk tea = milk +
      tea.” What property of equality does it show?
         a. Reflexive Property                  c. Transitive Property
         b. Symmetric Property                  d. Addition Property
                                          1
6. What is the first step in solving absolute value equations in one variable?
     a. Solve both equations.
      b. Let the expression on one side of the equation consist only of a single
         absolute value expression.
      c. If the absolute value of an expression is equal to a positive number, say
         a, then the expression inside the absolute value can either be a or –a.
         Equate the expression inside the absolute value sign to a and to –a.
      d. Determine if the number on the right side of the equation is negative or
         not. If its negative then there is no solution for the given, otherwise,
         proceed to step 3.
12. Which of the following graphs shows the solution of the equation 2x + 9 = 16?
a.
b.
c.
d.
                                       2
  13. Which of the following graph shows the solutions of the inequality 2x - 5 >
      6?
         a.
b.
        c.
        d.
a.
b.
c.
d. *
a. *
b.
c.
d.
       Let Us Study
        Finding the Solution of Linear Equation in One Variable
                                        3
Solution of a linear equation is a value, such that, when you replace the variable with
it, it makes the equation true. Linear equation in one variable can be written in the
form of ax + b = 0 where a and b are real numbers and a ≠ 0.
30 + 20 = ? We guess it is 30.
50 = 50 Therefore 30 is a solution.
Example: Given, 2x – 3 = 17, find the solution from the given replacement set
          {– 9, – 6, 0, 4, 10}.
Solution:
                                     2x – 3 = 17
   For x = – 9:      For x = – 6:     For x = 0:           For x = 4:          For x = 10:
  2(– 9) - 3 = ?   2(– 6) – 3 = ?    2(0) – 3 = ?         2(4) – 3 = ?        2(10) – 3 = ?
  – 18 – 3 = 17     – 12 – 3 = 17      0 – 3 = 17            8 – 3 = 17         20 – 3 = 17
      – 21 ≠ 17         – 15 ≠ 17        – 3 ≠ 17                5 ≠ 17             17 = 17
Properties of Equality
1. Reflexive Property of Equality
   For each real number a, a = a.
   Examples: a) 19 = 19           b) – d = – d             c) x + 5 = x + 5
2. Symmetric Property of Equality
   For any real numbers a and b, if a = b then b = a.
   Examples: a) If 10 + 9 = 19, then 19 = 10 + 9.     b) If x – 3 = 5, then 5 = x – 3.
3. Transitive Property of Equality
   For any real numbers a, b, and c, If a = b and b = c, then a = c.
   Examples: a) If 7 + 3 = 10 and 10 = 6 + 4, then 7 + 3 = 6 + 4.
               b) If x – 25 = y and y = 19, then x – 25 = 19.
                                           4
4. Substitution Property of Equality
   For any real numbers a and b: If a = b, then a may be replaced by b, or b may be
   replaced by a, in any mathematical sentence without changing its meaning.
   Examples: a) If p + d = 19 and p = 10, then 10 + d = 19.
              b) If 16 – x = 10 and x = 6, then 16 – 6 = 10.
      None, because subtracting or dividing the same number from both sides of an
equation are already covered by APE and MPE. Subtracting the same number from
both sides of an equality is the same as adding a negative number to both sides of
an equation. Dividing the same number from both sides of an equality is the same
as multiplying the reciprocal of the number to both sides of an equation.
Illustrative Examples
Example 1: Solve x + 21 = 3.
Solution:        x + 21 = 3               Given
          x + 21 + (-21) = 3 + (-21)      Add -21 to both sides of the equation (APE)
                      x = -18             final answer
Example 2: Solve x - 3 = 10.
Solution:        x - 3 = 10               Given
             x - 3 + 3= 10 + 3            Add 3 to both sides of the equation (APE)
                     x = 13               final answer
                                           5
Example 3: Solve 4x = 32.
Solution:        4x = 32                   Given
                  1                  1            1
              4x ∙ = 32 ∙                Multiply   to both sides of the equation (MPE)
                  4                  4            4
                  x=8                      final answer
                                                 1
Multiplying both sides of the equation with is the same with dividing both sides
                                            4
of the equation by 4. So, we can have an alternate solution of:
Solution:            4x = 32                Given
                     4x = 32                Divide both sides of the equation by 3(MPE)
                      4    4
                       x=8                  final answer
More Examples
Example 1: Solve and graph the solution of the linear equation 3x + 8 = 23.
               3x + 8 = 23                                      Given
        3x + 8 + (– 8) = 23 + (– 8)                Addition Property of Equality
                                                   Add both sides by negative 8
                   3x = 15                       Get the reciprocal of the coefficient
                                                      1/3 is the reciprocal of 3.
              1
                  ∙ 3x = 15 ∙
                                 1                     Multiplication Property
              3                  3
                                                     Multiply both sides by 1/3
                    x=5                                   The solution is 5.
Example 2: Solve and graph the solution of the linear equation 5x + 3 = x – 13.
           5x + 3 = x – 13                                      Given
      5x + 3 + (–3) = x – 13 + (–3)                Addition Property of Equality
                                                 Add both sides by negative 3 then
                  5x = x - 16                                 simplify.
                                                   Addition Property of Equality
        5x + (-x) = x + (-x) - 16                Add both sides by negative x then
                                                              simplify.
                  4x = - 16                           The reciprocal of 4 is .
                                                                              1
                                                                              4
             1
                  ∙ 4x = -16 ∙
                                 1               Multiplication Property of Equality
             4                   4                                              1
                                                      Multiply both sides by
                                                                                4
                    x=-4                                 The solution is - 4.
.
The graph shows the solution of the equation 5x + 3 = x – 13.
                                             6
         Finding the Solution of Linear Inequality in One Variable
Solution of an inequality is a value, such that, when you replace the variable with
it, it makes the inequality true. Linear inequality in one variable can be written in
the form of ax + b ≥, >, ≤, < 0 where a and b are real numbers and a ≠ 0.
Example 1. Given, x – 7 ≤ 15, find the solution/s from the given replacement set
        {– 9, 0, 22, 23, 30}.
                                       x – 7 ≤ 15
   For x = – 9:       For x = 0:       For x = 22:       For x = 23:       For x = 30:
 – 9 – 7 ≤ 15         0 – 7 ≤ 15     22 – 7 ≤ 15       23 – 7 ≤ 15       30 – 7 ≤ 15
  –16 ≤ 15, true   – 7 ≤ 15, true    15 ≤ 15, true     16 ≤ 15, false    23 ≤ 13, false
Based on the answers, part of the solution set are -9, 0, and 22.
Example 2. Given, 2x + 1 > 11, find the solution/s from the given replacement set
        {– 6, 5, 6, 12, 15}.
                                         2x + 1 > 11
For x = – 6:        For x = 5:         For x = 6:         For x = 12:        For x = 15:
2(– 6) + 1 > 11     2(5) + 1 > 11      2(6) + 1 > 11      2(12) + 1 > 11     2(15) +1 > 11
 – 12 + 1 > 11      10 + 1 >11         12 + 1 > 11        24 + 1 > 11        30 + 1 > 11
–11 > 11, false     11 > 11, false     13 > 11, true      25 > 11, true      31 > 11, true
Based on the answers, part of the solution set are 6, 12, and 15.
Properties of Inequalities
1. Trichotomy Property
       For any number a and b, one and only one of the following is true: a < b, a =
       b, or a > b.
       Example: One and only one of the following is true: 3 < x, 3 = x, or 3 > x.
                                           7
3. Addition Property of Inequality (API)
      For all real numbers a, b and c: (a) if a < b, then a + c < b + c, and
      (b) if a > b, then a + c > b + c.
      Adding the same number to both a and b will not change the inequality.
      Examples:
      a) If x + 3 < 5, then x + 3 + 10 < 5 + 10.
      b) If x +15 > 5, then x + 15 + (-15) > 5 + (-15).
Example 1. Solve and graph the solutions of the linear inequality 7x – 4 ≥ 10.
                 7x – 4 ≥ 10                                             Given
             7x – 4 + 4 ≥ 10 + 4                             Addition Property of Inequality
                                                             Add 4 both sides then simplify.
                      7x ≥ 14                                    1
                                                                     is the reciprocal of 7.
                                                                 7
                  1                    1               Multiplication Property of Inequality
                      ∙ 7x   ≥ 14∙                                                         1
                  7                    7
                                                                Multiply both sides by
                                                                                           7
                                                  8
In symbols the solution set is {x|x ≥ 2}. The graph shows the solutions of
7x – 4 ≥ 10 which is x ≥ 2 .
Example 2. Solve and graph the solutions of the linear inequality – 3x + 5 ≤ – 16.
            – 3x + 5 ≤ – 16                                 Given
     – 3x + 5 + (–5) ≤ – 16 + (–5)               Add negative 5 both sides
              – 3x ≤ - 21                      (- 1/3) is the reciprocal of -3.
           1                                                                1
        − 3 ∙ −3x ≤ -21∙ − 13                   Multiply both sides by −
                                                                            3
In symbols the solution set is {x|x ≥ 7}. The graph shows the solutions of
– 3x + 5 ≤ – 16 which is x ≥ 7.
Step 1: Let the expression on one side of the equation consist only of a
        single absolute value expression.
Step 2: Determine if the number on the right side of the equation is negative or not.
        If its negative then there is no solution for the given, otherwise, proceed to
        step 3.
Step 3: If the absolute value of an expression is equal to a positive number, say a,
        then the expression inside the absolute value can either be a or –a. Equate
        the expression inside the absolute value sign to a and to –a.
Step 4: Solve both equations.
                                           9
Example 1: Solve and graph |2a + 4| – 6 = 20.
 Step 2: Determine if
 the number on the
                              Since the number on the right side, which is 26, is
 right side of the
                                        positive, we proceed to step 3.
 equation is negative or
 not.
We can check that these two solutions make the original equation true.
      If a = 11, then |2a + 4| – 6 = |2(11) + 4| – 6 = 26 – 6 = 20.
      Also, if a = -15, then |2a + 4| – 6 = |2(-15) + 4| – 6 = 26 – 6 = 20.
|8x + 1| = -3
 Step 2: Determine if the number on the         Since the number on the right side of
 right side of the equation is negative or      the equation, which is -3, is negative,
 not.                                          then the given absolute value equation
                                                           has no solution.
                                          10
Example 3: Solve and graph |x – 5| = |3x + 5|.
 Step 2: Determine if
 the number on the
                                 |3x + 5| is positive, so we proceed to step 3.
 right side of the
 equation is negative
 or not.
We can check now the two values of x if it satisfy the original equation. If x = -5 and
x = 0.
       |x – 5| = |3x + 5|                        |x – 5|   =   |3x + 5|
      |-5 – 5| = |3(-5) + 5|                     |0 – 5|   =   |3(0) + 5|
        |-10| = |-15 + 5|                          |-5|    =   |5|
            10 = 10, True                              5   =   5, True
                                          11
 Step 2: Determine if the
 number on the right side
                                  |x - 4| is positive, so we proceed to step 3.
 of the equation is
 negative or not.
                                         12
 Step 4: Solve both               x - 7 = +(7 - x)                 x - 7 = -(7 - x)
 equations.                       x-7=7-x                       x - 7 = -7 + x
                                  x+x=7+7                        x - x = -7 + 7
                                     2x = 14                         0=0
                                      2    2
                                       x=7                This is an identity equation.
                                                           This will always be true no
                                                          matter what the of x is. Thus,
                                                              all real numbers are
                                                           solutions to this equation.
The solution set in the original equation is the set of all real numbers, so its graph
shows infinity.
Example: Solve the inequality: |2x - 5| < 9 and graph the resulting statement.
Solution: Since the inequality involves a “less than” sign, so we set up the
expression in the absolute value as less than 9 and greater than -9.
                               |2x - 5| < 9
      Therefore, the solution of this inequality is {x|-2 < x < 7}. Graphing the result,
we shade the numbers that are less than 7 but greater than -2.
Note: We use an open circle if the final answer is not part of the solution set. If it is
part of the solution set, then we will use a closed circle.
                                           13
Case 2: To solve an absolute value inequality > or ≥, we express the inequality as an
equivalent disjunction.
Example: Solve the inequality: |2x - 1| ≥ 7 and graph the resulting statement.
Solution: Since the inequality involves a “greater than” or equal to sign, so we set up
the expression in the absolute value as less than or equal to -7 and greater than or
equal to 7.
|2x - 1| ≥ 7
        2x – 1 ≤ - 7          or            2x – 1 ≥ 7
           2x ≤ -7 +1         or               2x ≥ 7 + 1
           2x ≤ - 6           or               2x ≥ 8
            2     2                             2 2
             x≤-3             or                 x≥4
Let Us Practice
I-Directions:
A. Determine which among the given replacement set {–3, –2, –1, 0, 1, 2, 3} is the
solution for each equation.
   1)   x+5=4
   2)   x–3=–2
   3)   2x + 7 = 7
   4)   5x – 13 = – 3
   5)   3x + 2 = 2x - 1
                                            14
C. Fill-in the blanks with correct expressions indicated by the property of equality
to be used.
   1)   If 2 + 8 = 10, then 10 = ____ (Symmetric Property)
   2)   (80 + 4) · 2 = 84 · ____ (Multiplication Property)
   3)   11 + 8 = 19 and 19 = 10 + 9, then 11 + 8 = _____ (Transitive Property)
   4)   5 + 10 + (–10) = 15 + ____ (Addition Property)
   5)   10 = ____ (Reflexive Property)
D. Determine which among the given replacement set is part of the solution
for each inequality.
   1) 2x + 5 > 7 ; {–6, –3, 4, 8, 10}           4) 2x ≤ 3x –1 ; { –5, –3, –1, 1, 3 }
   2) 5x + 4 < –11 ; {–7, –5, –2, 0 }           5) 11x + 1 < 9x + 3 ; { –7, –3, 0, 3, 5}
   3) 3x – 7 ≥ 2; { –2, 0, 3, 6 }
   A. Solve the following linear equations in one variable applying the Properties of
      Equality. Show your solution.
        1) x + 6 = 10                    4) 2x - 3 = 13
        2) 5x – 4 = 11                   5) 5 – x = 3
        3) 2x = 8 – 16
   C. Solve the following absolute value equations and graph its solution set.
        1) |m| – 3 = 7                   4) |3a – 8| + 4 = 11
        2) |2v| – 4 = 8                  5) |10 – u| = |u – 10|
        3) |4x + 2| – 3 = –7
   D. Solve the following absolute value inequalities and graph its solution set.
        1) |x – 4| < 5                   4. |2x – 5| < 9
        2) |2x + 3| > 13                 5. |2x – 1| ≥ 7
        3) |3x – 7| – 4 > 10
                                          15
          Let Us Remember
Let us summarize important things about the lesson to guide us in finding the
solution of linear equations/inequalities in one variable.
   Step 1: Let the expression on one side of the equation consist only of a
    single absolute value expression.
   Step 2: Determine if the number on the right side of the equation is negative or
   not. If its negative then there is no solution for the given, otherwise, proceed to
   step 3.
   Step 3: If the absolute value of an expression is equal to a positive number, say
   a, then the expression inside the absolute value can either be a or –a. Equate the
   expression inside the absolute value sign to a and to –a.
        Let Us Assess
Multiple Choice. Let us assess what you have learned on the lesson by answering the
problems below. Write the letter of your answer on a piece of paper.
                                          16
3. Which of the following is NOT a solution of the inequality |2a - 6| > 12
      a. -12                b. 0                c. 10                d. 12
4. Given the replacement set (-3, - 2, -1, 0, 1, 2, 3), which of the following is/are the
   solution/s of the inequality 3x + 4 < 6?
         a. x = (-3, -1, 0, 2)                        c. x = (- 3, -2, -1, 0)
         b. x = (0, 1, 2, 3)                          d. x = ( -2,-1, 0, 1)
12. Which of the following graphs shows the solution of the equation 3x - 2 = 10?
a.
b.
c.
d.
                                                 17
13. Which of the following graphs shows the solution of the inequality 2x - 5 ≤ 6?
a.
b.
c.
d.
14. Which of the following graph shows the solutions of the equation |2x - 7| = 3?
a.
b.
c.
d.
15. Which of the following graph shows the solutions of the inequality |3x - 8| ≥
7?
a.
b.
c.
d.
                                         18
        Let Us Enhance
Procedure
    1. Create a situation in real-life where linear equation or inequality in one
       variable is applied. You may research some problems as your guide
       in creating a problem and then solve it whichever way you want.
    2. Prepare diagrams or pictures that will help us to visualize the
       situation/problem that you have made. You may also prepare the
       necessary table or graph to present the important data in your
       situation/problem and the correct equation or inequality and steps
       to solve the problem. Show that you know about the topic by using
       concepts about the properties of real numbers as applied in linear
       equations or inequalities in one variable to describe the situation.
    3. Timely, relevant, and pressing issues or situations such as the
       Covid19 pandemic, business, etc. that we face today are more
       encouraged.
            Score                                Descriptions
               5         Poses a more complex problem with two or more
                         solutions and communicates ideas unmistakably,
                         shows in-depth comprehension of the pertinent
                         concepts    and/or     processes and   provides
                         explanation           wherever      appropriate.
                         Equations/inequalities are properly formulated
                         and solved correctly.
               3         Poses a more complex problem and finishes all
                         significant parts of the solution and communicates
                         ideas      unmistakably,         shows     in-depth
                         comprehension of the pertinent concepts and/or
                         processes. Equations/inequalities are properly
                         formulated but not all are solved correctly.
               1         Poses a complex problem and finishes all
                         significant parts of the solution and communicates
                         ideas      unmistakably,         shows    in-depth
                         comprehension of the pertinent concepts and/or
                         processes. Equations/inequalities are properly
                         formulated but are not solved correctly.
                                       19
        Let Us Reflect
      Reflect on what you have learned about this week’s lesson on Solving Linear
Equations and Inequalities in One Variable. Check the box of the emoticon to show
what you thought about the lesson and state why you felt that way.
I feel ……………………
because _____________________________________________
__________________________________________________
__________________________________________________
__________________________________________________
_________________________________________________.
                                       20
                                                  21
Let Us Practice                                        Let Us Practice
                                                       A.
D.                                                     1. x = -1
1.   { 4, 8, 10}                                       2. x = 1
2.   { - 7, - 5}                                       3. x = 0
3.   {3, 6}                                            4. x = 2
4.   {1, 3}                                            5. x = -3
5.   {- 7, - 3, 0}
                                                       B.
E.                                                     1. Transitive Property of Equality
1. Transitive Property of Inequality                   2. Reflexive Property of Equality
2. Multiplication Property of Inequality               3. Addition Property of Equality
3. Addition of Property of Inequality                  4. Symmetry Property of Equality
4. Multiplication Property of Inequality               5. Multiplication Property of Equality
5. Trichotomy Property of Inequality
                                                       C.
                                                       1. 2 + 8
                                                       2. 2
                                                       3. 10 + 9
                                                       4. (-10)
                                                       5. 10
             Let Us Try
             1. d                          6. b                              11. a
             2. b                          7. a                              12. c
             3. a                          8. b                              13. b
             4. c                          9. a                              14. d
             5. b                          10. d                             15. a
                                                                   Answer Key
                                                    22
Let Us Practice More                                     Let Us Practice More
B.                                                       A.
1)                   x+4>7                               1)              x + 6 = 10
       x + 4 + (-4) > 7+ (-4)                 API             x + 6 + (-6) = 10 + (-6)                 APE
                           x>3                                                  x=4
2)                  5x – 8 < 22                          2)             5x – 4 = 11
       5x – 8 + 8 < 22 + 8                    API              5x – 4 + 4 = 11 + 4                     APE
                         5x < 30                                              5x = 15
                    1                 1                                  1                 1
                (       ) 5x < 30 (       )   MPI                   (        ) 5x = 15 (       )       MPE
                    5                 5                                  5                 5
                          x<6                                                   x=3
3)                  x + 7 ≤ 15                           3)                  2x = 8 – 16
      x + 7 + (-7) ≤ 15 + (-7) API                                           2x = - 8
                          x ≤8                                      1                      1
                                                                (       ) 2x = (- 8 )(             )   MPE
                                                                    2                      2
                                                                              x = -4
4)              3x + 4 ≥ 25
     3x + 4 + (-4) ≥ 25 + (-4) API
                3x ≥ 21                                  4)             2x - 3 = 13
                    1    1
                (
              ) 3x ≥ 21 ( ) MPI
                    3                 3                        2x - 3 + 3 = 13 + 3                     APE
                          x≥7                                                 2x = 16
                                                                        1                  1
                                                                    (        ) 2x = 16 (           )   MPE
                                                                        2                  2
5)         2x - 1 > 9                                                          x = 8
     – 2x - 1 + 1 > 9 + 1    API
             – 2x > 10
            1                         1                  5)                  5–x=3
       (- )(– 2x) < (10)(- ) MPI
            2                         2
                                                               5 + (-5) – x = 3 + (-5)                 APE
                          x<-5
                                                                                -x = - 2
                                                                ( -1 )( -x ) = (- 2 )( -1 ) MPE
                                                                                x=2
                                              23
Let Us Practice More
C.
 1) m = {– 10, 10}
 2) v =( – 6, 6)
 3) There is no graph because there is no solution.
          1
 4) a = { 3, 5 }
 5) All real numbers {u|u ∈ R} or R ( - ∞ , ∞ )
D.
 1) Solution Set: {x|-1 < x < 9}
 2) Solution Set: {x|x < -8} and {x|x > 5}
                             7
 3) Solution Set: {x|x < -       } and {x|x
                             3
 4) Solution Set: {x|- 2 < x < 7}
 5) Solution Set: {x|x ≤ - 3} and {x|x ≥ 4}
                                 15. a              10. c              5. d
                                 14. d               9. a              4. c
                                 13. c              8. d               3. b
                                 12. b              7. b               2. a
                                 11. c               6. c              1. c
Let Us Assess
References
Ricardo M. Crisostomo, et. al., Our World of Math: Quezon City: Vibal Publishing
      House Inc., 2013, 193-242.
                                         24
For inquiries or feedback, please write or call:
Telefax:
                            25
7
    Mathematics
    Quarter 2 – Module 7:
  Solving Problems Involving
Linear Equation and Inequality
        in One Variable
Mathematics – Grade 7
Quarter 2 – Module 7: Solving Problems Involving Linear Equation and Inequality in
                     One Variable
First Edition, 2020
       Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
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Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.
   Mathematics
    Quarter 2 – Module 7:
  Solving Problems Involving
Linear Equation and Inequality
        in One Variable
Introductory Message
                                       ii
         Let Us Learn
       Hello learners! Welcome to our lesson for this week which is to solve problems
involving linear equation and inequality in one variable (M7AL-IIj-2).
       Let Us Try
Direction: Read the following questions carefully and write the letter of the
correct answer on a separate sheet of paper.
   3. There are two numbers whose sum is 72. One number is twice the other. What
      are the numbers?
         a. 22 and 50                       c. 25 and 50
         b. 24 and 48                       d. 28 and 44
   4. The sum of two numbers is 52. If one number is -38, what is the other
      number?
         a. – 90       b. – 14           c. 14             d. 90
   5. The sum of three consecutive integers is 90. What is the middle integer?
         a. 28           b. 29                c. 30               d. 31
   7. A man’s age is 51 and that of his son is 7 years. In how many years will the
      man be 5 times as old as his son?
         a. 4            b. 6                 c. 8               d. 10
   8. If the weight of a sack of rice is multiplied by 2/3, the result is 32 kg. What
      is the weight of the sack of rice?
          a. 40 kg          b. 42 kg              c. 45 kg            d. 48 kg
                                           1
   9. If Manny can do twice as many push-ups as Joem, who does 48, how many
      push-ups can he do?
          a. 24          b. 50             c. 96             d. 100
   10. Aurora is 2 times older than Jessica. In 10 years, the sum of their ages is 50
       years. Find their present ages.
          a. Aurora is 10 and Jessica is 20. c. Aurora is 30 and Jessica is 10.
          b. Aurora is 20 and Jessica is 10. d. Both Aurora and Jessica are 25.
   11. Gigi has score 82, 91, 85, 92 on four summative tests. What is the least
       score she can get on the fifth test to have an average of more than 88?
          a. 89            b. 90                 c. 91               d. 92
   12. The difference between two numbers is greater than 50. If the larger number
       is 98, what is the possible smaller number?
           a. 47            b. 48              c. 49               d. 50
   13. There are seven less girls than boys in a class of less than sixty-one
       students. How many boys could possibly be there in a class?
          a. 33            b. 34                c. 35                 d. 36
   14. Twice a number added to 15 is at least 51. Which of the following best
       describes the number?
          a. The number is more than 18.       c. The number is at most 18.
          b. The number is less than 18.       d. The number is at least 18.
   15. The length of a rectangle is 3 cm more than its width. If the perimeter of the
       rectangle is at most 138 cm, what is the maximum width of the rectangle?
a. 31 cm b. 32 cm c. 33 cm d. 34 cm
Let Us Study
                                           2
                                  LINEAR EQUATIONS
  The sum of two numbers is 36. If the second number is four more than thrice
 the first, find the numbers.
 Let x be the first number.
 The problem tells us that the second number is “four more than thrice the first
 number.” Therefore, we can represent the second number as:
 second number = four more than thrice the first
                                  3x      +   4
 Also, we know that the sum of the numbers is 36.
 Therefore, our equation is
                                  x + (3x + 4) = 36
 Solving the equation, we have
   x + (3x + 4) = 36
            4x + 4 = 36                               Combine like terms.
            4x + 4 + (-4) = 36 + (-4)                 Addition Property of Equality
                   4x = 32                            Divide both side by 4
                    4     4
                    x =8
Number Problem
 Find five consecutive odd integers whose sum is 55.
                                                  3
 Solve the equation.
 x + (x + 2) + (x+4) + (x + 6) + (x + 8) = 55
 5x + 20 = 55                                                   Combine like terms.
 5x + 20 + (– 20) = 55 + (–20)                             Addition Property of Equality
 5x = 35                                                   Divide both sides by 5
 5      5
 x=7
The five consecutive odd integers are 7, 9, 11, 13, and 15. We can check that the
answers are correct if we observe that the sum of these integers is 55, as required
by the problem.
                                           7 + 9 + 11 + 13 + 15 = 55
                                                             55 = 55    correct
Age Problem
 Margie is 3 times older than Lilet. In 15 years, the sum of their ages is 38 years.
 Find their present ages.
Checking: Margie is 6 which is 3 times older than Lilet who’s only 2 years old. In 15
years, their ages will be 21 and 17. The sum of their ages is 21 + 17 = 38.
                                     Age now                In 15 years
                              Lilet     x=2             x + 15 = 2 + 15 = 17
                             Margie 3x = 3(2) = 6 3x + 15 = 3(2) + 15 = 6 + 15 = 21
                             Total                          17 + 21 = 38
                                                       4
         SOLVING PROBLEMS INVOLVING LINEAR INEQUALITIES
Number Relation
The sum of two non-negative integers is 15. Twice the larger integer is greater than
thrice the other integer. Find the least value of the larger integer.
Solution:
       Let x be the larger integer and 15 - x be the other integer.
We obtain the inequality 2x > 3(15 - x).
        2x > 3(15 - x)
        2x > 45 - 3x           Distribute 3 inside the parenthesis (means multiply
                                                        3)
   2x + 3x > 45 - 3x + 3x      Isolate x to the other side then add 3x to both sides
                                           (Addition Property of Equality)
            5x > 45
            5    5                              Divide both sides by 5
             x >9                 This means that the larger integer should be
                                               greater than 9.
      Check:
            Let us try x = 9                            Let us try x = 10
              2x > 3(15 - x)                                2x > 3(15 - x)
             2(9) > 3(15 - 9)                            2(10) > 3(15 -10)
              18 > 3 (6)                                   20 > 3(5)
              18 > 18      which is not true.               20 > 15 which is true.
Money Problem
Keith has P5 000.00 in a savings account at the beginning of the summer. He wants
to have at least P2 000.00 in the account by the end of the summer. He withdraws
P250.00 each week for food and transportation. How many weeks can Keith withdraw
money from his account?
Solution:
                                           5
Step 2:
        5000               -    250w              ≥        2000
 Amount at the         withdraw 250 each          At       Amount by the end of
 beginning                      week              least    the summer
       Therefore, Keith can withdraw money from his account not more than 12
weeks. We can check our answer as follows. If Keith withdraws P250 per week 12
times, then the total money withdrawn is P3000. Since he started with P5000, then
he will still have P2000 at the end of the summer.
Let Us Practice
    3. Jim is 4 years less than twice David’s age. The sum of their ages is 23. Find
       their ages.
    4. Maria has scores of 93, 86, and 89 on three tests. What must her average
       score on the next two tests be in order for her to have an average of 90?
    5. Alex is paid P 2,800 a week plus a commission of P 500 on each television set
       he sells. How many sets must he sell to make P 5,300 in a week?
Problem Solving. Solve the following problems on linear inequalities in one variable.
Show your step-by-step solution.
   1. The capacity of an elevator is at most 750 kg. Six passengers weighing a total
      of 425 kg are already inside the elevator. What is the maximum additional
      weight that the elevator can carry?
   2. The sum of two non-negative integers is 20. Twice the larger integer is greater
      than thrice the other integer. Find the least value of the larger integer.
                                         6
   3. Jacob wants to buy some pencils at a price of P4.50 each. He has no more
      than P55.00. What is the greatest number of pencils can Jacob buy?
   4. Maiah won 40 lollipops playing basketball at the school fair. She gave two to
      every student in her math class. She has at least 7 lollipops left. Find the
      maximum number of students in her class.
   5. Isaiah has P3 000.00 in a savings account at the beginning of the summer.
      He wants to have at least P1 000.00 in the account by the end of the summer.
      He withdraws P100.00 each week for food and transportation. How many
      weeks can Isaiah withdraw money from his account?
Let Us Remember
       There are problems in real life that require several answers. Those problems
use the concept of equation and inequality. Here are some points to remember when
solving word problems that use linear equations and inequalities in one variable.
Let Us Assess
Direction: Read the following questions carefully and write the letter of the
correct answer on a separate sheet of paper.
   1.    A man’s age is 36 and that of his daughter is 3 years. In how many years will
        the man be 4 times as old as his daughter?
           a. 8             b. 10               c. 12                 d. 14
                                           7
3. Belle bought a T.V. Set for Php 8249.36 and a watch for Php 1249.36. How
   much did she spend in all?
      a. Php6498.72                       c. Php9498.72
      b. Php8498.72                       d.Php 7498.72
4. The sum of three consecutive integers is 306. What is the largest integer?
      a. 103          b. 105               c. 107              d. 109
8. If Ramon can do twice as many push-ups as Nilo, who does 75, how many
   push-ups can he do?
       a. 37.5        b. 73             c. 150              d. 77
10. The difference between two numbers is less than 96. If the larger number is
    245, what is the possible smaller number?
       a. 96            b. 129             c. 149               d. 194
11. There are four more boys than girls in a class of less than fifty-two students.
    How many boys could possibly be there in a class?
       a. 13           b. 24                c. 25                  d. 28
12. Vivian is three years younger than twice Maricel’s age. The sum of their ages
    is at most 42. What are their oldest possible ages?
        a. Maricel is 27 and Vivian is 15.   c. Maricel is 30 and Vivian is 12.
        b. Maricel is 12 and Vivian is 30.   d. Maricel is 15 and Vivian is 27.
14. Tanya is 28 years older than Marcus. In 6 years, Tanya will be three times
    as old as Marcus. How old is Tanya now?
       a. 34            b. 36              c. 38                d. 40
       b.
                                       8
   15. Thrice a number subtracted from 15 is at most -12. Which of the following
       best describes the number?
          a. The number is at least 9.       c. The number is less than 9.
          b. The number is at most 9.        d. The number is more than 9.
Let Us Enhance
      With the learnings you have about solving problems involving linear equation
and inequality in one variable, do this activity in a separate sheet of paper.
       Create 1 real-life word problem, it could be age, number, money or number
relation problem.
Do the following:
Answer:_____________________________________________________________
      4. Checking:
      Answer:_____________________________________________________________
      RUBRICS
        Points   Descriptor
        15       Has answered all questions with correct solution
        10       Has answered all questions but has an error in the solution
        5        Has answered two questions only
                                        9
        Let Us Reflect
                                         10
                                                11
Let Us Practice More
   1.)   Let x be the additional weight that the elevator can carry
                                 425 + x ≤ 750
                    425 + (-425) + x ≤ 750 + (-425)
                                         x ≤ 325
                Therefore, the elevator can still carry a maximum additional weight of 325 kg.
   2.) Let x be the larger integer
         20 – x = the other integer
                                2x > 3 (20 – x)
                                2x > 60 – 3x
                          2x + 3x > 60 – 3x + 3x
                                5x > 60
                                5x > 60
                                 5     5
                                  x > 12
              Therefore, the least value of the larger integer is 13.
   3.) Let x be the number of pencils
                              4.50x ≤ 55
                              4.50x ≤ 55
                               4.50   4.50
                                  x ≤ 12.22
               Therefore, the greatest number of pencils that Jacob can buy is 12 pencils.
Let Us Practice:                                         Let Us Try:
                             16         39               1.   c   6. b    11.   c
   1.)   3.2 and 7.8 or           and
                             5          5                2.   b   7. a    12.   a
                                                         3.   b   8. d    13.   a
   2.)   22, 24, 26, 28, 30                              4.   d   9. c    14.   d
                                                         5.   c   10. b   15.   c
   3.)   David is 9 yrs old and Jim is 14
   4.)   92
   5.)   5 television sets
                                                                    Answer Key
                                                12
                                               Let Us Assess:
                                               1.    a          6. a        11.   a
                                               2.    d          7. a        12.   d
                                               3.    c          8. c        13.   a
                                               4.    a          9. d        14.   b
                                               5.    b          10. d       15.   a
Let Us Practice More
   4)   Let x be the number of students
                                 40 – 2x ≥ 7
                     40 + (-40) – 2x ≥ 7 + (-40)
                                    – 2x ≥ – 33
                                    – 2x ≤ – 33
                                    –2       –2
                                          x ≤ 16.5
               Therefore, the maximum number of students in Maiah’s Math class is 16
        students.
   5)   Let x be the number of weeks Isaiah can withdraw money from his account
                                3000 – 100x ≥ 1000
                   3000 + (-3000) – 100x ≥ 1000 + (-3000)
                                      – 100x ≥ - 2000
                                      – 100x ≤ - 2000
                                      – 100    - 100
                                             x ≤ 20
                Therefore, Isaiah can withdraw money from his account in 20 or less weeks.
        References
                                   13
For inquiries or feedback, please write or call:
Telefax:
14