Show how to compute the determinant of the matrix
\[A= \left[\begin{array}{cccc} 2 & 3 & 5 & -6 \\ 6 & -2 & 1 & 3 \\ 2 & 0 & 0 & 0 \\ -2 & -1 & -3 & -4 \end{array}\right] .\]
.Answer:
\[\operatorname{det}\ \left[\begin{array}{cccc} 2 & 3 & 5 & -6 \\ 6 & -2 & 1 & 3 \\ 2 & 0 & 0 & 0 \\ -2 & -1 & -3 & -4 \end{array}\right] = -164 \]