Answer:
5x - 15 + 2x + 90 = 180
180 since it's a flat line, and all the angles should add up to 180 which is angle AOB, 90 degrees is already given in the middle.
Simplify all the terms (The algebra portion)
7x - 15 + 90 = 180
7x + 90 = 195
7x = 105
x = 105/7
x = 15
now substitute in x for all these angles
2(15) = 30 degrees is the angle GOB
5(15) - 15 = 60 degrees is the angle AOF
60 + 90 + 30 = 180 degrees.
and x = 15
