9514 1404 393
Answer:
x = 10
Step-by-step explanation:
The exterior angle is equal to the sum of the remote interior angles.
(12x +12)° = 79° +(5x+3)°
7x = 70 . . . . . . . . divide by °; subtract 12+5x; collect terms
x = 10 . . . . . . . . divide by 7
