Answer:
x = 3
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
120° is an exterior angle of the triangle , then
15x + 5 + 22x + 4 = 120
37x + 9 = 120 ( subtract 9 from both sides )
37x = 111 ( divide both sides by 37 )
x = 3
