Item1.2.5.2.c

\begin{equation*} \left[ \begin{array}{rrrr|r} 1 \amp 0 \amp 0 \amp 3 \amp 3 \\ 0 \amp 1 \amp 0 \amp -2 \amp 1 \\ 0 \amp 0 \amp 1 \amp 3 \amp 4 \\ 0 \amp 0 \amp 0 \amp 3 \amp 3 \\ \end{array} \right] \end{equation*}
in-context