To solve the system of equations using Cramer’s Rule, we follow these steps.
Given system of equations:
1. 3x + 2y = 10
2. -6x + 4y = 4
Step 1: Write the system in matrix form A \cdot X = B
The system is:
\begin{bmatrix} 3 & 2 \\ -6 & 4 \end{bmatrix} \cdot \begin{bmatrix} x \\ y \
end{bmatrix} = \begin{bmatrix} 10 \\ 4 \end{bmatrix}
Where:
• A = \begin{bmatrix} 3 & 2 \\ -6 & 4 \end{bmatrix}
• X = \begin{bmatrix} x \\ y \end{bmatrix}
• B = \begin{bmatrix} 10 \\ 4 \end{bmatrix}
Step 2: Find the determinant of matrix A, denoted as \text{det}(A)
\text{det}(A) = (3)(4) - (-6)(2) = 12 + 12 = 24
Step 3: Find matrices A_x and A_y by replacing columns of A with the column matrix
B
• For A_x, replace the first column of A with B:
A_x = \begin{bmatrix} 10 & 2 \\ 4 & 4 \end{bmatrix}
\text{det}(A_x) = (10)(4) - (4)(2) = 40 - 8 = 32
• For A_y, replace the second column of A with B:
A_y = \begin{bmatrix} 3 & 10 \\ -6 & 4 \end{bmatrix}
\text{det}(A_y) = (3)(4) - (-6)(10) = 12 + 60 = 72
Step 4: Solve for x and y using Cramer’s Rule
x = \frac{\text{det}(A_x)}{\text{det}(A)} = \frac{32}{24} = \frac{4}{3}
y = \frac{\text{det}(A_y)}{\text{det}(A)} = \frac{72}{24} = 3
Final Solution:
x = \frac{4}{3}, \quad y = 3