REVIEW: Greatest Common Factor Name ___________________________________
Key Concept and Vocabulary Visual Model
The greatest common factor (GCF) of two
or more positive monomials is the product Prime factors Prime factors
of their common prime factors. of 48 of 90
2
2 2 3
Prime factorization: 3
GCF
2 5
165 = 3 5 11
210 = 2 3 5 7
The GCF of 165 and 210 Common prime factors
is 3 5 = 15.
GCF = 2 3 6
Skill Examples Application Example
1. 15 = 3 5 5. You have 48 red flowers, 60 yellow flowers,
30 = 2 3 5 and 84 white flowers. You want to make
GCF = 3 5 = 15 flower arrangements that have the same
number of each color. What is the greatest
2. 20 = 2 2 5 number of arrangements that you can make
28 = 2 2 7 if every flower is used?
GCF = 2 2 = 4
48 = 2 2 2 2 3
48 = 2 2 2 2 3
3.
90 = 2 3 3 5
60 = 2 2 3 5 GCF = 2 2 3
GCF = 2 3 = 6
84 = 2 2 3 7 = 12
18x = 2 3 3 x x x
3 You can make 12 arrangements.
4.
21x = 3 7 x x
2
GCF = 3 x x = 3x 2
PRACTICE MAKES PURR-FECT Check your answers at BigIdeasMath.com.
Find the greatest common factor.
6. 36 = GCF = 7. 70 = GCF =
45 = 98 =
8. 42 = GCF = 9. 154 = GCF =
105 = 231 =
10. 27y = GCF = 11. 56m5 = GCF =
3 4
54y = 68m =
12. CLOTH You have two pieces of cloth. One piece is 80 inches wide and the other is 96 inches
wide. You want to cut both pieces into strips of equal width that are as wide as possible.
How wide should you cut each strip? width =
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