Answer:
x = 2
Step-by-step explanation:
Lengths on the AD side of the triangle are 24/36 = 2/3 of the corresponding lengths on the AC side of the triangle. That means ...
(2/3)·12 = 6x -4
12 = 6x . . . . . . . simplify, add 4
12/6 = x = 2 . . . divide by 6