Answer
See answers below
Work Step by Step
We are given:
$Ax_i=b_i$
Hence,
$x_1=A^{-1}b_1=-\frac{1}{39}
\begin{bmatrix}
-2 & -5\\
7 & 2
\end{bmatrix}\begin{bmatrix}
1\\
2
\end{bmatrix}=-\frac{1}{39}\begin{bmatrix}
-12\\
-3
\end{bmatrix}=\frac{1}{13}\begin{bmatrix}
4\\
1
\end{bmatrix}$
$x_2=A^{-1}b_2=-\frac{1}{39}
\begin{bmatrix}
-2 & -5\\
7 & 2
\end{bmatrix}\begin{bmatrix}
4\\
3
\end{bmatrix}=-\frac{1}{39}\begin{bmatrix}
-23\\
-22
\end{bmatrix}=\frac{1}{39}\begin{bmatrix}
23\\
22
\end{bmatrix}$
$x_3=A^{-1}b_3=-\frac{1}{39}
\begin{bmatrix}
-2 & -5\\
7 & 2
\end{bmatrix}\begin{bmatrix}
-2\\
5
\end{bmatrix}=-\frac{1}{39}\begin{bmatrix}
-21\\
24
\end{bmatrix}=\frac{1}{13}\begin{bmatrix}
7\\
-8
\end{bmatrix}$
