Algebra I: 1,001 Practice Problems For Dummies

Chapter 10

Factoring Binomials

A binomial is an expression with two terms. The terms can be separated by addition or subtraction. You have four possibilities for factoring binomials: (1) factor out a greatest common factor, (2) factor as the difference of perfect squares, (3) factor as the difference of perfect cubes, and (4) factor as the sum of perfect cubes. If one of these methods doesn't work, the binomial doesn't factor when using real numbers.

The Problems You'll Work On

The problems in this chapter focus on the following:

• Factoring when the two terms are the difference of perfect squares (both the numbers and the variables must be perfect squares)
• Factoring when the two terms are the difference of perfect cubes (both the numbers and the variables must be perfect cubes)
• Factoring when the two terms are the sum of perfect cubes (both the numbers and the variables must be perfect cubes)
• Using more than one factorization technique in a problem

What to Watch Out For

When working through the steps necessary for factoring binomials, pay careful attention to the following:

• Recognizing when a number is a perfect square so you can apply the factorization technique
• Knowing enough of the perfect cubes to recognize them in binomials
• Using the correct sign between the first and second terms of the trinomial when factoring sums and differences of cubes
• Trying to factor the sum of perfect squares and mistaking it for the technique used with cubes
• Using the correct exponents when ...