In order to find which one is or isn't, you need to solve for the value of 'x'.
2x + 15 = 35
2x = 20
x = 10
Substitute x =10, into equation. If each side are not the same (i.e. 0=2), then that's the equation that is not equivalent,
Answer is B
Double check this. Chur! :)
Hope this makes sense.