what is the determinant of $m = \\begin{bmatrix}5&-5\\\\8&4\\end{bmatrix}$?\n20\n40\n60\n80

Explanation:

Step1: Recall determinant formula

For a 2x2 matrix $\begin{bmatrix}a&b\c&d\end{bmatrix}$, the determinant is $ad - bc$.

Step2: Identify matrix elements

Here $a = 5$, $b=- 5$, $c = 8$, $d = 4$.

Step3: Calculate determinant

$ad - bc=5\times4-(-5)\times8=20 + 40=60$.

Answer:

60