Answer:
3rd option: x= 40
Step-by-step explanation:
4x° +20°= 180° (adj. ∠s on a str. line)
Bringing constants to 1 side:
4x°= 180° -20°
Simplify:
4x°= 160°
Divide by 4 on both sides:
x°= 40°
Thus, x=40.
