1. The problem statement, all variables and given/known data Simplify... 2. Relevant equations Starting Equation: ³√9xy^4 * ³√12x³y 3. The attempt at a solution (Sorry ahead of time if this is sloppy) ³√9xy^4 * ³√12x³y - I broke up each part of the cubed roots to try and simplify them ³√9 * ³√x * ³√y * ³√y³ * ³√y * ³√12 * ³√x³ * ³√y³ - I then simplified the obvious cubed roots, and simplified √12 to 2√3: y * ³√9xy * 2x * ³√3y - This is where I'm stuck. I don't understand how I can simplify if further when 9 has no rational number that can be multiplied by itself 3 times to get to 9, yet apparently the answer to it doesn't have 9 under the radical. The answer, to help out anybody who wants to help me, is: 3xy * ³√4xy² Thanks for any help.