# How to Factor Out Variables

You can factor out variables from the terms in an expression. You factor out variables the same way as you do numbers *except *that when you factor out powers of a variable, the *smallest* power that appears in any one term is the most that can be factored out.

Variables represent values; variables with exponents represent the powers of those same values.

In an expression such as

the smallest power of *a* that appears in any term is

is the greatest common factor. You can’t factor anything else out of each term:

Check your work quickly by doing either of the following:

**Multiply through (distribute) your answer in your head to be sure that the factored form is equivalent to the original form.**This is the problem you began with, so you factored the variables out correctly!

**Scan the terms in parentheses to make sure that they don’t share the same variable.**The terms in parentheses don't share any common variables, so you're done!