# HELP with factoring and simplifying

• Aug 10th 2009, 09:37 AM
reiward
HELP with factoring and simplifying
I cant solve this problem. help please :) thanks

http://img219.imageshack.us/img219/6621/mathq.jpg

oh. the last term has the denominator of xcube - 2xsquared y + 2x ysquared - ycube.

hope you guys can answer. :)
• Aug 10th 2009, 01:13 PM
Matt Westwood
First thing I would do is to get the thing in the brackets on the RHS over a common denominator and simplifying it out to see what I get. Then I try factorising stuff and cancelling out where possible. How far have you got?
• Aug 11th 2009, 12:26 AM
Hello reiward
Quote:

Originally Posted by reiward
I cant solve this problem. help please :) thanks

http://img219.imageshack.us/img219/6621/mathq.jpg

oh. the last term has the denominator of xcube - 2xsquared y + 2x ysquared - ycube.

hope you guys can answer. :)

You'll find the following expressions useful:

$x^3 -2x^2y+2xy^2 - y^3 = (x-y)(x^2-xy+y^2)$

This will enable you to find the LCD of the two fractions in the last bracket; and

$x^3 + y^3 = (x+y)(x^2-xy+y^2)$

This will allow you to cancel a common factor once you've turned the 'divided by' fraction
'upside-down'.