Remark
Vertically opposite angles are equal, which means that 2x = y - x
Side by side angles are supplementary which, in this case 2x + (y + x) = 180o
Solution
From the first equation we get
2x = y - x Add x to both sides.
2x + x = y
3x = y
From the second equation we get
2x + (y + x) = 180 Remove the brackets
2x + x + y = 180
3x + y = 180 Substitute 3x = y in this equation
3x + 3x = 180
6x = 180
x = 180/6
x = 30
y = 3x
y = 3*30
y = 90
Answer
x = 30
y = 90