Solution: The GCF of 109 and 38 is 1
Methods
How to find the GCF of 109 and 38 using Prime Factorization
One way to find the GCF of 109 and 38 is to compare the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here:
What are the Factors of 109?
What are the Factors of 38?
Here is the prime factorization of 109:
10
9
1
109^1
10 9 1
And this is the prime factorization of 38:
2
1
×
1
9
1
2^1 × 19^1
2 1 × 1 9 1
When you compare the prime factorization of these two numbers, you can see that there are no matching prime factors. When this is the case, it means that there are no common factors between these two numbers. As a result, the GCF of 109 and 38 is 1.
Thus, the GCF of 109 and 38 is: 1
How to Find the GCF of 109 and 38 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 109 and 38 is to find and list all the factors of each number. Again, you can see how this is done by looking at the “Factors of” articles that are linked to above.
Let’s take a look at the factors for each of these numbers, 109 and 38:
Factors of 109: 1, 109
Factors of 38: 1, 2, 19, 38
When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 109 and 38 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 128 and 56?
What is the GCF of 55 and 141?
What is the GCF of 138 and 126?
What is the GCF of 26 and 61?
What is the GCF of 131 and 101?