No diagram is provided but we can still work it out (it may vary).
So the from the description, we can tell that m∠EGB = m∠FHC through alternate exterior angles.
So,
m∠EGB = 2x + 40
m∠FHC = 3x - 10
m∠EGB = m∠FHC
2x + 40 = 3x - 10
40 = 3x - 2x - 10
40 = x - 10
40 + 10 = x
50 = x
x = 50
The value of x is 50