Item1.2.5.1.b

The reduced row echelon form is

\begin{equation*} \left[\begin{array}{rrrr|r} 1 \amp 0 \amp 0 \amp 0 \amp -1 \\ 0 \amp 1 \amp 0 \amp 0 \amp 0 \\ 0 \amp 0 \amp 0 \amp 1 \amp 1 \\ \end{array}\right]\text{.} \end{equation*}

The variable \(x_3\) is a free variable and all other variables are basic.

in-context