the solution to your problem is shown in the attached picture.
number 1 tells you the exponential rule that is being used.
numbers 2 and 3 tell you the exponential to radical conversion rules that are being used.
number 3 tells you the solution to your problem using the rule in number 1.
numbers 5 and 6 tell you the solution to your problem in radical form using the rules in numbers 2 and 3.
numbers 7 through 10 show you that each form provides you with the same answer, as they should.
the answer to your question is in number 4.
that answer is 3^(7/27).
i believe it can't be simplified further than that.
