Answer
See answers below
Work Step by Step
The coefficient matrix is: $A=\begin{bmatrix}
1 & 2& -1\\
2 & 3 & -2 \\
5 & 6 &-5
\end{bmatrix}$
The right-hand side vector is: $b=\begin{bmatrix}
0 \\
0\\
0
\end{bmatrix}$
The augmented matrix: $A^{\#}=\begin{bmatrix}
1 & 2& -1 | 0\\
2 & 3 & -2 | 0\\
5 & 6 &-5 | 0
\end{bmatrix}$
