Respuesta :

Answer:

x=20

Step-by-step explanation:

The line is a straight line, which is 180 degrees

x+100+3x = 180

Combine like terms

100+4x = 180

Subtract 100 from each side

100+4x-100=180-100

4x=80

Divide by 4

4x/4 = 80/4

x=20