Answer:
x = 20
y = 12
Explanation:
opposite angles are congruent so we can set up this equation:
5x + 29 = 7x - 11
29 = 2x - 11
40 = 2x
x = 20
5(20) + 29 = 129
7(20) - 11 = 129
3y + 15 = 5y - 9
15 = 2y - 9
24 = 2y
y = 12
3(12) + 15 = 51
5(12) - 9 = 51