# Homework Help: Simplifying Cubed Roots

1. May 17, 2012

### AnTiFreeze3

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.

Last edited: May 17, 2012
2. May 17, 2012

### ehild

What is really under the roots? Use parentheses! Bring everything under a single cubic root.

ehild

3. May 17, 2012

### AnTiFreeze3

Alright, thanks for the help. So, since I have a coefficient and similar variables under the cubed roots, I can change around where they all go?

And at first, I thought ehild was trying to call me a child for not knowing the answer, and just misspelled it.....

Last edited by a moderator: May 21, 2012