Cool Math
Coolmath: Difference of Two Squares, Sum and Difference of Two Cubes
This algebra lesson explains how to factor the difference of two squares and the sum and difference of two cubes.
CK-12 Foundation
Ck 12: Algebra Ii: 1.9 Sum and Difference of Cubes
This section expands on the process of factoring to certain types of polynomials. In particular, it investigates how to find the sum and difference of cubed numbers and terms, and it will use volume of cubes to model this process.