----------------------
Factoring rules needed:

The difference of two squares factors like this:


The sum of two cubes factors like this:
To factor 

The difference of two cubes factors like this:
To factor 
----------------------

We factor  by writing it as .
So it's the difference of two cubes with  and 
So it factors as 

We factor  by writing it as .
So it's the sum of two cubes with  and 
So it factors as 

We factor  by writing it as .
So it's the difference of two squares with  and 
So it factors as 

So we replace everything by its factorization:

. 

We can cancel the 's

.

And also we can cancel the 's

.

That leaves:



It's not necessary, but you can FOIL
out the numerator and get



Edwin