Same-side interior angles where a transversal meets parallel lines are supplementary. That means
... 60° + (2x -y)° = 180°
... 40° + (2x +y)° = 180°
You can subtract the second equation from the first and you get
... 20° -2y° = 0°
... 10 = y
Checking the two answers where y=10 in either of the above equations, you find the only one that works is ...
... B. x = 65, y = 10
