Answer
$-17$
Work Step by Step
The determinant of a $2\times2$ matrix $A=\begin{bmatrix}a & b\\c&d
\end{bmatrix}$ is given by $ad-bc.$ Hence, the determinant of the given matrix, $
\begin{bmatrix}
-1&3\\5&2
\end{bmatrix}$ is
\begin{align*}\require{cancel}
&
-1(2)-5(3)
\\&=
-2-15
\\&=
-17
.\end{align*}