The greatest common factor (GCF) is the greatest number that is a factor of two or more numbers. The first step for finding a GCF is to break down each number into its factors. We will write down all of the factors that are common between the given numbers.
Given number
Factors
Common Factors
27
1,3,9,27
1, 3, 9
45
1,3,5,9,15,45
1, 3, 9
For the given values, the common factors are 1, 3, and 9. Therefore, the greatest common factor between 27 and 45 is 9.
