My Math Forum  

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

Algebra Pre-Algebra and Basic Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
December 20th, 2007, 02:46 PM   #1
n30
Newbie
 
Joined: Dec 2007

Posts: 5
Thanks: 0

Simplying an Algebraic function

Hi there,
It would be great if someone could simply this algebraic function for me, I tried few times, but I'm not getting the same answer as the textbook. Thanks in advance.

Quote:
((-3x^2y^3) - (3x^6/y))/y^6
This is answer they have in the textbook:

Quote:
(-3x^2(y^4 + x^4)) / y^7
n30 is offline  
 
December 20th, 2007, 03:45 PM   #2
Senior Member
 
Joined: Apr 2007

Posts: 2,140
Thanks: 0

((-3x^2y^3) - (3x^6/y)) / (y^6)
= ((-3x^2y^3) - (3x^6/y))(y) / (y^6)(y)
= ((-3x^2y^4) - (3x^6)) / (y^7)
= (-3x^2(y^4+x^4)) / (y^7)
johnny is offline  
December 20th, 2007, 05:37 PM   #3
n30
Newbie
 
Joined: Dec 2007

Posts: 5
Thanks: 0

Quote:
Originally Posted by johnny
((-3x^2y^3) - (3x^6/y)) / (y^6)
= ((-3x^2y^3) - (3x^6/y))(y) / (y^6)(y)
= ((-3x^2y^4) - (3x^6)) / (y^7)
= (-3x^2(y^4+x^4)) / (y^7)
johnny, you are the man! Thanks alot for solving it out for me. You wouldn't believe but I spent more than 1 hour tryina figure out how they got the answer. One thing that I'm still not too sure about is that, why did u have to multiply both sides, (-3x^2y^3) AND (3x^6/y) by "y"? what is wrong with only multiplying 3x^6/y by "y". Hope to hear from you soon. Once again, Thank you for your help !
n30 is offline  
December 20th, 2007, 05:56 PM   #4
Senior Member
 
Joined: Apr 2007

Posts: 2,140
Thanks: 0

Multiplying 3x^6/y by y is important. In order to do this, we have to multiply ((-3x^2y^3) - (3x^6/y)) by y. I'll generalize this below.

In algebraic operations, we can say that (a - b)(c) = ac - bc.

So, at ((-3x^2y^3) - (3x^6/y)) / (y^6), if we want to get rid of the denominator y of 3x^6/y, we have to multiply by y, and to make the algebra easier, multiply the whole parenthesis part by y, and you can get rid of denominator y, and that's pretty much it.

Let me know if you have question.
johnny is offline  
December 20th, 2007, 06:41 PM   #5
n30
Newbie
 
Joined: Dec 2007

Posts: 5
Thanks: 0

it makes sense, johnny. Thank you !
n30 is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
algebraic, function, simplying



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Algebraic expressions Confused dude Algebra 28 January 30th, 2013 03:08 PM
Algebraic Fractions bilano99 Algebra 4 June 8th, 2012 07:43 AM
Simplying Trig brian890 Trigonometry 3 November 25th, 2011 09:43 PM
Algebraic differentiation jaspertml Calculus 1 January 5th, 2010 03:44 PM
Find the derivative of the algebraic function. imcutenfresa Calculus 3 September 15th, 2009 07:58 PM





Copyright © 2019 My Math Forum. All rights reserved.