Answer:
x = 6
Step-by-step explanation:
Alternate angles are congruent.
7x - 9 = 3x + 15 {Subtract 3x form both sides}
7x - 3x -9 = 15
4x - 9=15 {Add 9 to both sides}
4x = 15+9
4x = 24
x = 24/4
