Answer:
x = 35
Step-by-step explanation:
Since they are vertical angles, the angles are congruent and therefore you can set them equal to each other.
4x + 20 = 3x + 55
Have x on one side of the equation by subtracting 3x from both sides.
x + 20 = 55
Subtract 20 from both sides of the equation.
x = 35
