Answer: 100 degrees
===============================================================
Explanation:
The two angles that involve x are alternate interior angles.
Due to the parallel lines, the alternate interior angles are equal.
We'll use this to solve for x
-7x-18 = -9x-46
-7x+9x = -46+18
2x = -28
x = -28/2
x = -14
Let's check the answer by evaluating each expression as shown below
- -7x-18 = -7*(-14)-18 = 80
- -9x-46 = -9*(-14)-46 = 80
Both angles are 80 degrees each, so it confirms we have the correct x value.
-----------------------
We have one last step. We found the -9x-46 angle to be 80 degrees. Angle 4 is adjacent to this and supplementary.
So we subtract from 180 to get the answer
180-80 = 100
