Item1.2.5.3.c

\(\left[\begin{array}{rrrrr|r} 1 \amp 0 \amp 0 \amp -2 \amp 3 \amp 7 \\ 0 \amp 1 \amp 0 \amp 3 \amp 0 \amp 4 \\ 0 \amp 0 \amp 1 \amp 1 \amp -1 \amp 2 \\ \end{array}\right]\text{.}\)

in-context