1) Simplify:

I know I can split it up like below, but I'm finding it hard to remember where to go next.

It's obvious that both 9 and 15 are factors of 45, but, in terms of exponents, I can't remember the order of operations from here.

2) Simplify:

I know thata^(1/n) = nth root of a, but I can't seem to get the correct answer.

Thanks in advance.