Hotmath
Math Homework. Do It Faster, Learn It Better.

Greatest Common Factor of Monomials

To find the greatest common factor of two monomials, first find the prime factorization of each monomial, including all the variables (and a 1 factor if necessary).

Then take the product of all common factors.

Example:

Find the GCF of:

27 p 2 q r 5

and

15 p 3 r 3

First, find the prime factorization of each monomial.

27 p 2 q r 5 = 1 3 3 3 p p q r r r r r 15 p 3 r 3 = 3 5 p p p r r r

Common factors are shown in red. Their product is:

3 p p r r r

So, the GCF is 3 p 2 r 3 .