Answer
$3$
Work Step by Step
The determinant of a $2 \times 2$ matrix can be computed by using the formula $det =ps-qr$
where $det =\begin{vmatrix}p & q \\r & s\end{vmatrix}$
$-2\begin{vmatrix} -1 & 0` \\1 & 4\end{vmatrix}-1 \begin{vmatrix} 2 &3 \\ 1 & 4\end{vmatrix}+0=-2(-4-0)-1(8-3)$
or, $=8-5$
or, $=3$
