Answer: A. 20 is the answer.
Step-by-step explanation:
x+40 = 3x
or, 40 = 3x-x
or, 2x = 40
or, x = 40/2
so, x = 20
Y=112 because of vertical angles or if you subtract 68 from 180 to get it.
It is the division property of equality. You divide by 5 each side of the equation to isolate x.