Answer:
11. x = 5
12. x = 24
Step-by-step explanation:
11.
8x° + 140° = 180°
(Linear pair angles)
8x° = 180° - 140°
8x° = 40°
x ° = 40°/8
x° = 5°
x = 5
12.
2x° + 42° = 90°
(complementary angles)
2x° = 90° - 42°
2x° = 48°
x ° = 48°/2
x° = 24°
x = 24
