Answer:
x = 50
Step-by-step explanation:
The two angles are vertical angles, so they are congruent. Congruent angles have equal measures. Set the angle measures equal to each other, and solve the equation for x.
2(x + 10) = 3x - 30
Distribute on the left side.
2x + 20 = 3x - 30
Subtract 2x from both sides.
20 = x - 30
Add 30 to both sides.
50 = x
x = 50
