Create an equation to solve for x then solve for x.

Step-by-step explanation:

In parallelogram adjacent angles are supplementary

∠U +∠V = 180

9x + 15 + 6x + 15 = 180

Combine like terms

9x + 6x + 15 + 15 = 180

          15x + 30 = 180

Subtract 30 from both sides

          15x = 180 - 30

         15x = 150

Divide both sides by 15

            x = 150/15

x = 10

∠U = 9x + 15

      = 9*10 + 15

      = 90 + 15

∠U = 105

∠V = 6x + 15

     = 6*10 + 15

     = 60 + 15

∠V = 75