Answer:
-82
Step-by-step explanation:
Maybe you want the determinant of ...
[tex]\left[\begin{array}{cc}5&9\\8&-2\end{array}\right][/tex]
The determinant of a 2×2 matrix is the difference of the products of elements on the down diagonal and the up diagonal:
D = (5)(-2) -(8)(9) = -10 -72 = -82
The determinant of this matrix is -82.