» » » If | 2 3 | = | 4 1 |. find the value of y. 7

# If | 2 3 | = | 4 1 |. find the value of y. 7

### Question

If | 2 3 | = | 4 1 |. find the value of y. 7

A)
-6
B)
6
C)
-12
D)
12

### Explanation:

$$\begin{vmatrix} 2 & 3 \\ 5 & 3x \end{vmatrix}$$ = $$\begin{vmatrix} 4 & 1 \\ 3 & 2x \end{vmatrix}$$
(2 x 3x) - (5 x 3) = (4 x 2x) - (3 x 1)
6x - 15 = 8x - 3
6x - 8x = 15 - 3
-2x = 12
x = $$\frac{12}{-2}$$
= -6

## Dicussion (1)

• $$\begin{vmatrix} 2 & 3 \\ 5 & 3x \end{vmatrix}$$ = $$\begin{vmatrix} 4 & 1 \\ 3 & 2x \end{vmatrix}$$
(2 x 3x) - (5 x 3) = (4 x 2x) - (3 x 1)
6x - 15 = 8x - 3
6x - 8x = 15 - 3
-2x = 12
x = $$\frac{12}{-2}$$
= -6