If the index and exponent in a radical expression are the same, the simplest form will be the radicand itself. You will just have to cancel out both the exponent and the radical sign, together with the index of course.
For example, I have the radical expression [tex]\sqrt[3]{5^3}[/tex]. The index is 3, the same as the exponent of the radicand 5. Cancel out the index and exponent. [tex]\sqrt[\cancel{3}]{5^{\cancel{3}}}[/tex] The results will be 5.
How is it? Happy learning!
