Answer
$ \left[\begin{array}{cc|c}
1 & -3 & 1\\
0 & 7&-7
\end{array}\right]$.
Work Step by Step
The given matrix is
$\Rightarrow \left[\begin{array}{cc|c}
1 & -3 & 1\\
2 & 1& -5
\end{array}\right]$
Perform $R_2\rightarrow -2R_1+R_2$.
Multiply the first row by $-2$ and add to the second row.
$\Rightarrow \left[\begin{array}{cc|c}
1 & -3 & 1\\
-2(1)+2 & -2(-3)+ 1&-2(1)+ (-5)
\end{array}\right]$
Simplify.
$\Rightarrow \left[\begin{array}{cc|c}
1 & -3 & 1\\
0 & 7&-7
\end{array}\right]$.
