Hey there!
To simplify radical expressions, refer to the conversion of a radical expression to a number with an exponent:
[tex] \sqrt[a]{x} = x^{\frac{1}{a} } [/tex]
Remember that if you don't see an index, there is an implied "2" that will go where "a" is.
Depending on your problem, you could also cancel a radical by raising the entire expression by the second power (only if your index is 2).
Hope this helped you out! :-)