Hi!
All the angles on the blue line are equal 180 degrees. The angle between 7x and 5x is 20 degrees, it is the same as the one on the other side. Knowing that:
20 + 7x + 90 = 180
7x = 70
x = 10
All the angles on the green line are equal 180 degrees, so:
7x + 20 + 5x + 2y = 180
2y = 180 - 20 - 50 - 70
2y = 40
y = 20
Hope this helps!