Why have you encountered this equation? Perhaps it is only a thought / property question. Rephrase in words and think about it.
What number is alterered identically by a power and a root.
The square is the square root.
The cube is the cube root.
There are not too many candidates.
Does it make a difference if x is positive or negative?
Does it make a difference if n is odd or even?
Again, why have you encountered this equation?