Questions: Solve the system using inverse matrices.
5x - 2y = 30
x + 6y = -26
Transcript text: Solve the system using inverse matrices.
\[
\begin{array}{c}
\left\{\begin{array}{l}
5 x-2 y=30 \\
x+6 y=-26
\end{array}\right. \\
\end{array}
\]
Solution
Solution Steps
To solve the system of equations using inverse matrices, we first represent the system in matrix form \( AX = B \), where \( A \) is the coefficient matrix, \( X \) is the column matrix of variables, and \( B \) is the column matrix of constants. We then find the inverse of matrix \( A \) and multiply it by matrix \( B \) to find matrix \( X \), which contains the solutions for \( x \) and \( y \).
Step 1: Set Up the System of Equations
We start with the system of equations given by:
\[
\begin{align_}
5x - 2y &= 30 \quad (1) \\
x + 6y &= -26 \quad (2)
\end{align_}
\]
This can be represented in matrix form as \( AX = B \), where:
\[
A = \begin{bmatrix} 5 & -2 \\ 1 & 6 \end{bmatrix}, \quad X = \begin{bmatrix} x \\ y \end{bmatrix}, \quad B = \begin{bmatrix} 30 \\ -26 \end{bmatrix}
\]
Step 2: Calculate the Inverse of Matrix A
To solve for \( X \), we first need to find the inverse of matrix \( A \):
\[
A^{-1} = \begin{bmatrix} 0.1875 & 0.0625 \\ -0.03125 & 0.15625 \end{bmatrix}
\]
Step 3: Solve for X
Next, we multiply the inverse of \( A \) by \( B \) to find \( X \):
\[
X = A^{-1}B = \begin{bmatrix} 0.1875 & 0.0625 \\ -0.03125 & 0.15625 \end{bmatrix} \begin{bmatrix} 30 \\ -26 \end{bmatrix} = \begin{bmatrix} 4 \\ -5 \end{bmatrix}
\]
Final Answer
Thus, the solution to the system of equations is:
\[
\boxed{x = 4, \, y = -5}
\]