Explanation:

In mathematics, factorization (also factorisation in British English) or factoring is the decomposition of an object (for example, a number, a polynomial, or a matrix) into a product of other objects, or factors, which when multiplied together give the original.  For example, the number 15 factors into primes as 3 × 5, and the polynomial x² − 4 factors as (x − 2)(x + 2). In all cases, a product of simpler objects is obtained.

The aim of factoring is usually to reduce something to "basic building blocks," such as numbers to prime numbers, or polynomials to irreducible polynomials.

Sum/difference of two squares

Another common type of algebraic factoring is called the difference of two squares. It is the application of the formula

to any two terms, whether or not they are perfect squares. If the two terms are subtracted, simply apply the formula. (Our solved example in mathguru.com uses this concept)

http://en.wikipedia.org/wiki/Factorization

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