Answer/Step-by-step explanation:
9. 17x = 16x + 5 (alternate exterior angle)
17x - 16x = 5
x = 5
Measure of bolded angle = 17x = 17 * 5 = 85
10. 21x - 6 = 20x (corresponding angels)
21x - 20x = 6
x = 6
Measure of bolded angle = 20x = 20(6) = 120
11. (x + 95) + (x + 105) = 180 (linear pair angles)
2x + 200 = 180
2x = 180 - 200
2x = -20
Divide both sides by 2
x = -10
Measure of bolded angle = x + 105 = -17 + 105 = 88°
12. 12x - 4 = 11x + 3 (vertical angles)
Collect like terms
12x - 11x = 4 + 3
x = 7
Measure of bolded angle = 11x + 3 = 77 + 3 = 80°
