My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum

LinkBack Thread Tools Display Modes
March 6th, 2014, 07:06 PM   #1
Joined: Mar 2014

Posts: 1
Thanks: 0

cube root

What is the cube root of (81x^8y^12)?

It is probably super easy, but after several tries, I just give up. Thank you so much!!!

Given answers:

A) 3x^2y^4 cube root of (3x^2)
B) 3x^2y^4 fifth root of (3x^2)
C) 3x^2y^12 cube root of (3x^2)
D) 3x^2y^4 cube root of (3xy)
lila342 is offline  
March 6th, 2014, 07:29 PM   #2
Math Team
Joined: Dec 2013
From: Colombia

Posts: 7,696
Thanks: 2681

Math Focus: Mainly analysis and algebra
Re: cube root

The cube root of any product is the product of the cube root of each elements of the product.

That is:

Also and

Armed with that, you should be able to have another go.
v8archie is offline  
March 6th, 2014, 07:40 PM   #3
Math Team
Joined: Sep 2007

Posts: 2,409
Thanks: 6

Re: cube root

HallsofIvy is offline  
March 6th, 2014, 08:13 PM   #4
Global Moderator
greg1313's Avatar
Joined: Oct 2008
From: London, Ontario, Canada - The Forest City

Posts: 7,974
Thanks: 1156

Math Focus: Elementary mathematics and beyond
Re: cube root

When multiplying exponentials with the same base, add the exponents. The above uses that rule "in reverse".
greg1313 is offline  
March 7th, 2014, 12:57 AM   #5
Global Moderator
Joined: Dec 2006

Posts: 21,105
Thanks: 2324

Originally Posted by lila342
. . . after several tries, I just give up.
There are only four choices, and the second choice is absurd (the third choice also, if given a moment's thought), so how could you need more than three tries?
skipjack is offline  

  My Math Forum > High School Math Forum > Algebra

cube, root

Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Help with Cube Root: achintya Algebra 10 April 5th, 2013 11:33 AM
Cube root of 2 mathmaniac Algebra 49 March 25th, 2013 06:48 PM
Cube Root of -1 Niko Bellic Algebra 6 March 6th, 2013 07:18 PM
challenging cube root problem peri123 Number Theory 2 August 19th, 2008 10:00 AM
Cube root of 2 mathmaniac Number Theory 0 December 31st, 1969 04:00 PM

Copyright © 2019 My Math Forum. All rights reserved.