Question

Solve for x and y.

parallel lines  

x = 12, y = 14


x = 4, y = 14


x = 8.6, y = 4


x = 12, y = 4

Answer 1

Because the two lines are parallel, the vertically opposite angles will be congruent, and because of the definition of supplementary angles, you can set (15x - 5) = 180 - 125 then solve for x.
15x -5 = 55
15x = 60
x = 4
There's only one option when x = 4, so y must = 14.