Answer:
x=25
Explanation:
Since the line is straight, its degrees sum up to 180°. Because of this, you can subtract 60 from 180 to get 120°. Now you know that the missing angle measures 120°. Since you know this, you can set 4x+20 equal to 120. Subtract 20 from both sides to get 4x=100, then divide 100 by 4 to get 25. x=25.