Factors
Recall that when two or more numbers are multiplied, each number is a factor of the product. We all know that 3 • 6 = 18, 3 and 6 are called factors but 18 is called a product.
Some whole numbers have exactly two factors, the number itself and 1. Recall that these numbers are called prime numbers. Whole numbers that have more than two factors, such as 12, are called composite numbers.
4 •3 = 12 , 4 is a factor of 12. However, it is not a prime factor of 12 because 4 is not a prime number. Recall that when a number is expressed as a product of prime factors, the expression is called the prime factorization of the number.
The prime factorization of 12 is 2•2•3
The greatest common factor of two (or more) integers is the largest integer that is a factor of both (or all) numbers.
The greatest common factor of two (or more) monomials is the product of the greatest common factor of the numerical coefficients (the numbers out in front) and the least power of every variable that is a factor of each monomial.
To find out more about factors, read the explanation below.
Practice: Answer the following exercises about factors.