##### Matrix operations - part 7
###### Find the determinant of the matrix: $\begin{bmatrix} 4 &-9 \\ 2& 7 \end{bmatrix}$

$\begin{bmatrix} 4 &-9 \\ 2& 7 \end{bmatrix}$ = 4 X 7 - 2 X -9 = 24 - (-18) = 24 + 18 =  42