1. **State the problem:** Solve the system of linear equations using the inverse matrix method:
$$\begin{cases} 2x - 3y = -1 \\ -3x + 5y = 3 \end{cases}$$
2. **Write the system in matrix form:**
$$AX = B$$
where
$$A = \begin{bmatrix} 2 & -3 \\ -3 & 5 \end{bmatrix}, \quad X = \begin{bmatrix} x \\ y \end{bmatrix}, \quad B = \begin{bmatrix} -1 \\ 3 \end{bmatrix}$$
3. **Formula for the inverse of a 2x2 matrix:**
For
$$A = \begin{bmatrix} a & b \\ c & d \end{bmatrix},$$
its inverse is
$$A^{-1} = \frac{1}{ad - bc} \begin{bmatrix} d & -b \\ -c & a \end{bmatrix}$$
provided that the determinant $ad - bc \neq 0$.
4. **Calculate the determinant:**
$$ad - bc = (2)(5) - (-3)(-3) = 10 - 9 = 1$$
Since the determinant is 1 (not zero), the matrix is invertible.
5. **Find the inverse matrix:**
$$A^{-1} = \frac{1}{1} \begin{bmatrix} 5 & 3 \\ 3 & 2 \end{bmatrix} = \begin{bmatrix} 5 & 3 \\ 3 & 2 \end{bmatrix}$$
6. **Multiply the inverse matrix by B to find X:**
$$X = A^{-1}B = \begin{bmatrix} 5 & 3 \\ 3 & 2 \end{bmatrix} \begin{bmatrix} -1 \\ 3 \end{bmatrix} = \begin{bmatrix} 5(-1) + 3(3) \\ 3(-1) + 2(3) \end{bmatrix} = \begin{bmatrix} -5 + 9 \\ -3 + 6 \end{bmatrix} = \begin{bmatrix} 4 \\ 3 \end{bmatrix}$$
7. **Interpret the solution:**
The solution to the system is $x = 4$ and $y = 3$.
This means the point $(4, 3)$ satisfies both equations.
**Summary:** We used the inverse matrix method by first writing the system as $AX = B$, then finding $A^{-1}$ using the formula for 2x2 matrices, and finally multiplying $A^{-1}$ by $B$ to get the unique solution vector $X$.
Inverse Matrix 762Caf
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