# Math Help - Guidelines wanted (dead or alive)

1. ## Guidelines wanted (dead or alive)

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.

2. 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