Answer:
57°
Step-by-step explanation:
Exterior Angle Theorem: An exterior angle of a triangle is equal to the sum of the opposite interior angles.
(9x+16) + (6x+15) = 136
15x + 31 = 136
15x = 105
x = 7
plug into (6x + 15)
6(7) + 15 = 42 + 15 = 57
