Itemb

Does the following linear system have exactly one solution, infinitely many solutions, or no solutions?

\begin{equation*} \begin{alignedat}{4} -x \amp {}-{} \amp 2y \amp {}+{} \amp 2z \amp {}={} \amp -1 \\ 2x \amp {}+{} \amp 4y \amp {}-{} \amp z \amp {}={} \amp 5 \\ x \amp {}+{} \amp 2y \amp \amp \amp {}={} \amp 3 \\ \end{alignedat} \end{equation*}
in-context