Question

solve using matrices
x+3y=13
2x-y=-9

Answer 1

pull the coefficients and constants, then row reduce

Answer 2

\[\begin{align}x+3y&=13\\
2x-y&=-9\end{align}\]
\[\begin{bmatrix}1&3\\2&-1\end{bmatrix}\begin{bmatrix}x\\y\end{bmatrix}=\begin{bmatrix}13\\-9\end{bmatrix}\]
\[\left[\begin{array}{cc|c}1&3&13\\2&-1&-9\end{array}\right]\]