Step-by-step explanation:
exterior angle is the sum of two opposite interior angle
11x+9=3x+12+85
11x-3x=88
8x=88
x=11.
hope this helps you.
Answer:
x=11
85 + 3x + 12= 11x+9
97 +3x= 11x+9
-97 -97
3x= 11x - 88
-11x -11x
-8x = -88
/-8 /-8
