This question isn't really worded in a way where I can help you, as it could mean (1 - x)^3/2 = 2x or it could mean 1 - x^3/2 = 2x, both of which fit your wording but will give different answers. If you can tell me which one of these it is, then i can help you, but unfortunately I can't help you with the wording how it is at the moment :/