Respuesta :

9514 1404 393

Answer:

  A.  9

Step-by-step explanation:

The exterior angle is equal to the sum of the remote interior angles.

  10x -19 = (3x +2) +(5x -3)

  2x = 18 . . . . . . . . . . . . . . . add 19-8x to both sides, simplfy

  x = 9 . . . . . . . . . . . divide by 2