Factoring A GCF From an Expression

To best understand this lesson, you should make sure you know how to find the GCF of two or more terms. To learn how, see the lesson called Finding a GCF.

3x³ + 27x² + 9x

To factor out the GCF in an expression like the one above, first find the GCF of all of the expression's terms.

3	(1, 3)
27	(1, 3, 9, 27)
9	(1, 3, 9)

GCF = 3x

Next, write the GCF on the left of a set of parentheses:

3x(               )

Next, divide each term from the original expression (3x³+27x²+9x ) by the GCF (3x), then write it in the parenthesis.

3x³ / 3x = x²
27x² / 3x = 9x
9x / 3x = 3

3x(x² + 9x + 3)

Proceed to the next page to try another problem.