Matrix Determinant

Find the determinant of the following 2 x 2 matrix:

Hint
Hint 2
$$$\begin{bmatrix}a_{1} & a_2\\ b_1 & b_2\end{bmatrix}=(a_{1})(b_2)-(a_2)(b_1)$$$
$$$\begin{bmatrix}a_{1} & a_2\\ b_1 & b_2\end{bmatrix}=(a_{1})(b_2)-(a_2)(b_1)$$$
$$$\begin{bmatrix}4 & 5\\ 6 & 7\end{bmatrix}=(4)(7)-(5)(6)=28-30=-2$$$
-2