Respuesta :

Simple...

you have: The angles are supplementary..what is the measure of angle x? 

Remember, supplementary means 180°

4x+20+40=180

4x+60=180

4x+60=180
     -60  -60

4x=120

x=30

Thus, your answer.
4x+20+40=180
4x+60=180
4x=120
x=30

From: Dark Angel >:)