Here's the question you clicked on:
mitchelsewbaran
nth root of 64 minus the nth root of (27)=1, that is the value of 4^n? 256 144 64 54 4
Well, I'm not sure if this is the way you're supposed to solve it, but just by looking at it, I know that 64 and 27 are both equal powers of a certain number...by thinking a bit you'll be able to find what n is.
Try finding the prime factorization of 64 and 27, that might help you see what type of power they both are.
If you're having trouble with that, think about it. What numbers multiplied together make 64? Which make 27?