Solution: The GCF of 139 and 99 is 1
Methods
How to find the GCF of 139 and 99 using Prime Factorization
One way to find the GCF of 139 and 99 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 139?
What are the Factors of 99?
Here is the prime factorization of 139:
13
9
1
139^1
13 9 1
And this is the prime factorization of 99:
3
2
×
1
1
1
3^2 × 11^1
3 2 × 1 1 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 139 and 99 is 1.
Thus, the GCF of 139 and 99 is: 1
How to Find the GCF of 139 and 99 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 139 and 99 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, 139 and 99:
Factors of 139: 1, 139
Factors of 99: 1, 3, 9, 11, 33, 99
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 139 and 99 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 146 and 138?
What is the GCF of 78 and 109?
What is the GCF of 119 and 92?
What is the GCF of 24 and 11?
What is the GCF of 76 and 113?