Find the Determinant [[10,8],[20,12]]

$[\begin{array}{c} 10 & 8 \\ 20 & 12 \end{array}]$

Step 1

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

$10 \cdot 12 - 20 \cdot 8$

Step 2

Simplify the determinant.

Simplify each term.

Multiply $10$ by $12$ .

$120 - 20 \cdot 8$

Multiply $- 20$ by $8$ .

$120 - 160$

Subtract $160$ from $120$ .

$- 40$