Answer:
-8
Step-by-step explanation:
m∠3 + m∠5 = 180 (interior angles are supplementary)
-4x + 5 + (-13x + 39) = 180
-4x + 5 -13x +39 = 180
-17x = 180 - 5 - 39
-17x = 136
x = 136/(-17) = -8
