Answer:
x = 12
Step-by-step explanation:
The exterior angle is equal to the sum of the opposite interior angles
3x+19 + 5x = 115
Combine like terms
8x + 19 = 115
Subtract 19 from each side
8x+19 -19 = 115 -19
8x = 96
Divide each side by 8
8x/8 = 96/8
x =12
