#### Answer

$-22$

#### Work Step by Step

The general formula to calculate the determinate of a $2 \times 2$ matrix which has 2 rows and 2 coulmns is
$D=\begin{vmatrix}a&b\\c&d\end{vmatrix}=ad-bc$
Now,
$D=\begin{vmatrix}1&-3\\-8&2\end{vmatrix}=2-24=-22$