# Guidelines wanted (dead or alive)

• November 24th 2008, 11:03 AM
Alienis Back
This is the problem: $16x^3y^2-4xy^2$

...and what I tried to do:

$16x^3y^2-4xy^2$

$4xy^2\left(4x^2-1\right)$

$4xy^2\left(4x^2-1^2\right)$

$4xy^2\left(4x-1\right)\left(4x+1\right)$

But then when trying to solve it in order to check the answer, comes to something different.(Headbang)
• November 24th 2008, 11:05 AM
Moo
Hello,

You thought correctly with the difference of two squares.

The only problem is this :

$4x^2-1=({\color{red}2x})^2-1^2=(2x-1)(2x+1)$

just a very little careless mistake, but your working is good :)