Vertical angles are congruent or equal to each other.
Set the equation:
8x - 8 = 7x + 8
Add 8 to both sides of the equation.
8x - 8 + 8 = 7x + 8 + 8
8x = 7x + 16
Subtract 7x from both sides of the equation.
8x - 7x = 7x - 7x + 16
x = 16
Answer: D) 16
Checking to see if our answer is right.
8x - 8 = 7x + 8
8(16) - 8 = 7(16) + 8
128 - 8 = 112 + 8
120 = 120