If (begin{vmatrix} 2 & 3 \ 5 & 3x end{vmatrix}) = (begin{vmatrix} 4 & 1 \ 3 & 2x end{vmatrix}), find the value of x.
-
A.
-6 -
B.
6 -
C.
-12 -
D.
12
Correct Answer: Option A
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