For each of the following augmented matrices write out the corresponding linear system of equations. Solve the system by applying Gaussian Elimination to the augmented matrix.
(a) $\left(\begin{array}{rr|r}3 & 2 & 2 \\ -4 & -3 & -1\end{array}\right)$,
(b) $\left(\begin{array}{rrr|r}1 & 2 & 0 & -3 \\ -1 & 2 & 1 & -6 \\ -2 & 0 & -3 & 1\end{array}\right)$,
(c) $\left(\begin{array}{rrrr|r}2 & -1 & 0 & 0 & 0 \\ -1 & 2 & -1 & 0 & 1 \\ 0 & -1 & 2 & -1 & 1 \\ 0 & 0 & -1 & 2 & 0\end{array}\right)$.