Factor the expression

Step-by-step explanation:

Your difference of perfect cubes formula is given as

and you have already correctly identified a as  and b as . So we fill in the formula as follows:

and we simplify.  Remember that

. It's important that you remember the rules.

Simplifying then gives us

That's it, so fill it in however you need to on your end. Learn the patterns for the sum and difference of cubes and it will save you a ton of headaches...promise!!