Question

Find the value of x.

• 5
• 20
• 40
• 45​

Answer 1

3rd option: x= 40

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.