#### Answer

x = -1
y = 1
z = 3
w = 1

#### Work Step by Step

The reduced row-echelon form of the matrix is:
$\begin{bmatrix}
1 & 0 & 0 & 0 & |-1\\
0 & 1 & 0 & 0 & |1\\
0 & 0 & 1 & 0 & |3\\
0 & 0 & 0 & 1 & |1\\
\end{bmatrix}$
From reduced row-echelon form the solution is simple:
x = -1
y = 1
z = 3
w = 1