Answer:
x = 20
Step-by-step explanation:
When two parallel lines are intersected by a transversal, then the alternate exterior angles are congruent.
5x + 20 = 3x + 60
Now subtract 3x form both sides
5x - 3x + 20 = 3x - 3x + 60
2x + 20 = 60
Subtract 20 from both sides
2x + 20 -20 = 60 - 20
2x = 40
Divide both sides by 2
x = 40/2
x = 20
