Because it's a parellelogram, we can assume DH and HF are parallel, and we can assume GH and HE are parallel. Set DH and HF equal to each other to solve for x, and GH and HE equal to each other to solve for y. You would use system of equations.
Solving for y:
x + 3 = 3y
x=3y-3
2x-5=5y+2
2(3y-3)-5=5y+2
6y-6-5=5y+2
6y-11=5y+2
y=13
Solving for x:
x+3=3y
y=(1/3)x+1
2x-5=5y+2
2x-5=5((1/3)x+1)+2
2x-5=(5/3)x+5+2
2x-5=(5/3)x+7
2x=(5/3)x+12
(1/3)x=12
x=36