.
Go from here.
x^n = y^n sometimes has more solutions than just x = y.
Simplest example: x^2 = y^2 could be x = -y
Also, when raising to a power, we may actually have fewer solutions:
Consider sqrt(x) = -sqrt(y), squaring both sides gives x = y, but
sqrt(x) = -sqrt(x) is only true when x=0.
It is always a good idea to plug solutions back into the original equation to check.
For this problem, all solutions check out.