Answer: x = 30
Explanation:
According to the Congruent Vertical Angle theoreum, opposite vertical angles must be equal.
Therefore, we can equal both angles to each other.
4x - 40 = x + 50
Now, solve for x. Move x over to the other side.
4x - 40 - x = 50
Subtract the x's.
3x - 40 = 50
Now, add 40 to the other side to isolate the 3x.
3x = 90
Divide by 3.
x = 30
Hope this helps! :)