Respuesta :

Answer:

x = 30

Step-by-step explanation:

Angles on a line equal 180

4x + 20 + 40 = 180

4x + 60 = 180

Minus 60 on both sides.

4x = 120

Divide by 4 on both sides.

x = 30

4x + 20 + 40 = 180
4x + 60 = 180
4x = 120
x = 30