Answer
$0$
Work Step by Step
The determinant of a $2 \times 2$ matrix can be computed by using the formula $det =ps-qr$
where $det =\begin{vmatrix}p & q \\r & s\end{vmatrix}$
So, $\begin{vmatrix} 6& 3 &-7 \\0 & 0 & 0 \\ 4 &-6 & 3\end{vmatrix}=0 \begin{vmatrix} 3 & -7 \\-6 & 3\end{vmatrix}+0 \begin{vmatrix} 6 &-7 \\ 4 & 3\end{vmatrix}+0\begin{vmatrix} 6& 3 \\ 4 &-6\end{vmatrix}$
or, $=0$
