The angles across from each other equal each other.
3y + 5 = y + 75 (subtract 5 from each side)
3y = y + 70 (subtract y from each side)
2y = 70 (divide by 2)
Y = 35
Do same thing with X.
3x +7 = 5x - 35 (subtract 7 from each side)
3x = 5x - 42 (subtract 5x)
-2x = -42 (divide by -2)
X = 21
Plug in each number to make sure it equals