Answer
$54$
Work Step by Step
We will evaluate the determinant of the given matrix using the rule:
$$A=\begin{bmatrix}a&b&c\\d&e&f\\g&h&i\end{bmatrix}$$
$$det A=(aei+bfg+cdh)-(ceg+ahf+bdi).\tag1$$
Calculate the determinant of the given matrix using formula $(1)$:
$$\begin{align*}
det A&=(-24+4+60)-(-48+4+30)=54\\
\end{align*}$$
