Question

Find the determinant of the given matrix. -42 or -22 or 22 or 42

Answer 1

Answer:

A. $-42$

Step-by-step explanation:

We have been given a 2 by 2 matrix. We are asked to find the discriminant for our given matrix.

The discriminant for our given matrix would be product of negative 2 and 5 minus product of 4 and 8.

$\text{Discriminant}=5\times -2-4\times 8$  

$\text{Discriminant}=-10-32$

$\text{Discriminant}=-42$

Therefore, the discriminant for our given matrix is $-42$ and option A is the correct choice.

Answer 2

Answer:

-42

Step-by-step explanation:

Cross multiply

5 * -2 = -10

8 * 4 = 32

-10 - 32 = -42