###### Item 1.2.5.1.a

The reduced row echelon form is

\begin{equation*}
\left[\begin{array}{rr|r}
1 \amp 0 \amp -1 \\
0 \amp 1 \amp 2 \\
0 \amp 0 \amp 0 \\
\end{array}\right]\text{,}
\end{equation*}

and there is a single solution. Every variable is basic.