Question

I have my geometry midterm on Friday and I don't know how to do this problem. Someone help?

Answer 1

Since the lines u and v are parallel, this means that the angles (10x - 5) = (7x + 4)
and that 7x + 4 + y = 180. 

You can solve the first equation for x, then substitute that value into the second equation and rearrange for y. 

10x - 5 = 7x +4
3x -5 = 4
3x = 9
x = 3°

∴ 7(3) + 4 + y = 180
25 + y = 180
∴ y = 180 - 25
 y = 155°