1. **State the problem:** Solve the system of equations:
$$x - 4y = -5$$
$$-3x + 5y = 1$$
2. **Write the system in tabular (augmented matrix) form:**
$$\begin{bmatrix} 1 & -4 & | & -5 \\ -3 & 5 & | & 1 \end{bmatrix}$$
3. **Use row operations to solve:**
- Start with the matrix:
$$\begin{bmatrix} 1 & -4 & | & -5 \\ -3 & 5 & | & 1 \end{bmatrix}$$
- Add 3 times row 1 to row 2 to eliminate $x$ from row 2:
$$R_2 \to R_2 + 3R_1$$
$$\begin{bmatrix} 1 & -4 & | & -5 \\ \cancel{-3} + 3 \times 1 & 5 + 3 \times (-4) & | & 1 + 3 \times (-5) \end{bmatrix} = \begin{bmatrix} 1 & -4 & | & -5 \\ 0 & -7 & | & -14 \end{bmatrix}$$
- Divide row 2 by $-7$ to make the pivot 1:
$$R_2 \to \frac{1}{-7} R_2$$
$$\begin{bmatrix} 1 & -4 & | & -5 \\ 0 & \cancel{-7} \times \frac{1}{-7} & | & \cancel{-14} \times \frac{1}{-7} \end{bmatrix} = \begin{bmatrix} 1 & -4 & | & -5 \\ 0 & 1 & | & 2 \end{bmatrix}$$
- Add 4 times row 2 to row 1 to eliminate $y$ from row 1:
$$R_1 \to R_1 + 4R_2$$
$$\begin{bmatrix} 1 & \cancel{-4} + 4 \times 1 & | & -5 + 4 \times 2 \\ 0 & 1 & | & 2 \end{bmatrix} = \begin{bmatrix} 1 & 0 & | & 3 \\ 0 & 1 & | & 2 \end{bmatrix}$$
4. **Solution:**
$$x = 3, \quad y = 2$$
Thus, the exact solution is $(3, 2)$.
Solve Linear System 04A82E
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