
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
August 9th, 2015, 12:38 PM  #1 
Newbie Joined: Aug 2015 From: UK Posts: 9 Thanks: 0  Factorizing 16x^481y^4, why is the answer written like this?
I can understand how the answer is reached: square root both sides to make it (4x^2 + 9y^2) (4x^2  9y^2) Then factorize the latter brackets to get a final answer of (4x^2 + 9y^2) (2x + 3y) (2x  3y) Is the reason for not factorizing further with the first set of brackets because the answer would be the same for both brackets as (2x + 3y) (2x + 3y) or (2x  3y) (2x  3y)? Why is this done? I want to be extra sure about the rules on this. 
August 9th, 2015, 02:11 PM  #2 
Math Team Joined: Jul 2011 From: Texas Posts: 3,094 Thanks: 1676 
$4x^2+9y^2$ is not factorable over the real numbers

August 9th, 2015, 09:40 PM  #3 
Global Moderator Joined: Dec 2006 Posts: 21,107 Thanks: 2324  
August 10th, 2015, 11:00 AM  #4  
Senior Member Joined: Feb 2010 Posts: 714 Thanks: 151  Quote:
You can perform the same operation to both sides of a relation ($\displaystyle =,<,$ etc.) As has been pointed out, what you want in this problem is to apply the wellknown factor pattern called difference of squares $\displaystyle x^2y^2=(x+y)(xy)$  

Tags 
16x481y4, answer, factorizing, written 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Factorizing.  jiasyuen  Algebra  10  January 23rd, 2015 02:09 PM 
Factorizing.  jiasyuen  Algebra  3  December 31st, 2014 10:06 PM 
factorizing  gelatine1  Number Theory  4  August 27th, 2013 09:49 PM 
Why in the answer written all discharge  rsoy  Physics  0  March 1st, 2012 08:06 AM 
factorizing problem  apohz  Algebra  3  April 15th, 2009 09:43 AM 