Answer
$7$
Work Step by Step
The determinant $D$ of a $ 2 \times 2$ matrix can be calculated as:
$D=\left|\begin{array}{ll}
A & B\\C & D \end{array}\right|=AD-BC$
The determinant $D$ of a given $ 2 \times 2$ matrix can be calculated as:
$D=\left|\begin{array}{ll}
-1 &-2\\ 5 & 3 \end{array}\right|=(-1)(3)-(-2)(5)=-3+10=7$
