Answer:
x = 10
Explanation:
We know that in a parallelogram base angles are supplementary angle (add up to 180°)
Given that;
∠U = 9x + 15
∠V = 6x + 15
we can say that:
∠U + ∠V = 180°
(9x + 15) + (6x + 15) = 180
Combining like terms we get;
15x + 30 = 180°
15x = 180 - 30
15x = 150
x = 150/15
x = 10
Hope this helps!