Help me on this pls and thank you

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

the answer is 31.27mph