Answer:
x = 34
Step-by-step explanation:
This is a straight line so the sum of angles must be 180°
4x + 20 + x - 10 = 180 add like terms
5x + 10 = 180 subtract 10 from both sides
5x = 170 divide both sides by 5
x = 34
To calculate each angle we replace x with the value we found
4x + 20 ➡ 4×34 + 20 = 156
x - 10 ➡ 34 - 10 = 24
