Each augmented matrix is in row-echelon form. Assume that the variables are $x, y,$ and $z$ and use back-substitution to obtain the solution of the associated system of linear equations.
$$
\left[\begin{array}{rrr|r}
1 & -3 & -1 & -3 \\
0 & 1 & -\frac{1}{4} & \frac{1}{2} \\
0 & 0 & 1 & 2
\end{array}\right]
$$