Answer:
x should equal 26.
Step-by-step explanation:
since they are cointerior angles:
2 (x + 15) + (3x + 20) = 180
2 (x) + 2 (15) + (3x + 20) = 180
2x + 30 + (3x + 20) = 180
2x + 30 + 3x + 20 = 180
5x + 50 = 180
5x + 50 - 50 = 180 - 50
5x = 130
5 ÷ 5x = 130 ÷ 5
x = 26
