\sim \left(
\begin{array}{ccccc}
 1 & 7 & 6 & -1 & 7 \\
 0 & -3 & -4 & 0 & -6 \\
 0 & -11 & -10 & 4 & -12 \\
 0 & 4 & 3 & -2 & 3 \\
 0 & -12 & -9 & 6 & p-14
\end{array}
\right)
\begin{array}{c}
 \text{II}(-11)+\text{III}(3) \\
 \text{II}(4)+\text{IV}(3) \\
 \text{II}(-4)+V
\end{array}
\sim \left(
\begin{array}{ccccc}
 1 & 7 & 6 & -1 & 7 \\
 0 & -3 & -4 & 0 & -6 \\
 0 & 0 & 14 & 12 & 30 \\
 0 & 0 & -7 & -6 & -15 \\
 0 & 0 & 7 & 6 & p+10
\end{array}
\right)
\begin{array}{c}
 \text{III}+\text{IV}(2) \\
 \text{III}+V(-2)
\end{array}
\sim \left(
\begin{array}{ccccc}
 1 & 7 & 6 & -1 & 7 \\
 0 & -3 & -4 & 0 & -6 \\
 0 & 0 & 14 & 12 & 30 \\
 0 & 0 & 0 & 0 & 0 \\
 0 & 0 & 0 & 0 & -2p+10
\end{array}
\right)