Answer:
Step-by-step explanation:
Exterior angle property: Exterior angles equals the sum of remote angles
19x - 18 = 7x + 1 + 10x - 9
19x - 18 = 7x + 10x + 1 - 9 {Combine like terms}
19x - 18 = 17x - 8 {Subtract 17x from both sides}
19x - 17x - 18 = -8
2x - 18 = -8 {Add 18 to both sides}
2x = -8 + 18
2x = 10
x = 10/2
x = 5
