Solution: The GCF of 87 and 34 is 1
Methods
How to find the GCF of 87 and 34 using Prime Factorization
One way to find the GCF of 87 and 34 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 87?
What are the Factors of 34?
Here is the prime factorization of 87:
3
1
×
2
9
1
3^1 × 29^1
3 1 × 2 9 1
And this is the prime factorization of 34:
2
1
×
1
7
1
2^1 × 17^1
2 1 × 1 7 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 87 and 34 is 1.
Thus, the GCF of 87 and 34 is: 1
How to Find the GCF of 87 and 34 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 87 and 34 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, 87 and 34:
Factors of 87: 1, 3, 29, 87
Factors of 34: 1, 2, 17, 34
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 87 and 34 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 129 and 37?
What is the GCF of 21 and 50?
What is the GCF of 48 and 147?
What is the GCF of 123 and 138?
What is the GCF of 64 and 104?