Respuesta :

9514 1404 393

Answer:

  x = 35

Step-by-step explanation:

The marked consecutive interior angles are supplementary:

  (x +12)° +(4x -7)° = 180°

  5x +5 = 180 . . . . . collect terms, divide by °

  x + 1 = 36 . . . . . . . divide by 5

  x = 35 . . . . . . . . . . subtract 1