Item1.2.5.2.b

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