### Multiply the row to make the red cell a one.

\(\left[\begin{array}{rrr|r}\large\color{Red} {3} & -3 & -1 & -16 \\
-1 & 4 & 5 & -12 \\
-3 & -2 & -5 & 36\end{array}\right]\begin{array}{ll}\large\phantom{1} & \\
\phantom{1} & \\
\phantom{1} & \end{array}\)