given that A and B are parallel, you can conclude that 30 = x - y since they are corresponding angles. Also you can conclude that 5y = 2x since they are alternate interior angles. At this point, there is a solvable system of equations set up
30 = x - y
5y = 2x
Now, you must isolate a variable so let's isolate x from the 1st equation. so u just need to add y to both sides, getting x = 30 + y. Now you plug that into the 2nd equation and solve for y. 5y = 60 + 2y. Subtract 2y from both sides. 3y = 60. Divide by 3, y = 20.
Now with your y value, just plug back into original equation (the 1st one). 30 = x - 20. Solve for x by adding 20. X = 50
