Find the Determinant [[-8,-8],[6,9]]

$[\begin{array}{c} - 8 & - 8 \\ 6 & 9 \end{array}]$

Step 1

The determinant of a $2 \times 2$ matrix can be found using the formula $| \begin{array}{c} a & b \\ c & d \end{array} | = a d - c b$ .

$- 8 \cdot 9 - 6 \cdot - 8$

Step 2

Simplify the determinant.

Simplify each term.

Multiply $- 8$ by $9$ .

$- 72 - 6 \cdot - 8$

Multiply $- 6$ by $- 8$ .

$- 72 + 48$

Add $- 72$ and $48$ .

$- 24$