Answer:
u = 119
Step-by-step explanation:
The sum of the angles of a triangle add to 180
31+ u-40 + u-49 = 180
Combine like terms
2u -58 = 180
Add 58 to each side
2u-58+58 = 180+58
2u =238
Divide each side by 2
2u/2 = 238/2
u =119
