Respuesta :

9514 1404 393

Answer:

  x = 10

Step-by-step explanation:

In a parallelogram, adjacent angles are supplementary.

  (9x +15) +(6x +15) = 180

  15x +30 = 180 . . . . . . . . . . simplify

  15x = 150 . . . . . . . . . subtract 30

  x = 10 . . . . . . . . divide by 15