I've been racking my brain on this one and I have no idea on where to even start, so any help would be appreciated!

Let A and B be infinite sets with the same cardinality. Prove that P(A) and P(B) have the same cardinality. Do this by givingexplicitlya bijective function from P(A) to P(B). You must also prove that your function is indeed a bijection (show that it is 1-1 and onto).