Solution: The GCF of 129 and 54 is 3
Methods
How to find the GCF of 129 and 54 using Prime Factorization
One way to find the GCF of 129 and 54 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 129?
What are the Factors of 54?
Here is the prime factorization of 129:
3
1
×
4
3
1
3^1 × 43^1
3 1 × 4 3 1
And this is the prime factorization of 54:
2
1
×
3
3
2^1 × 3^3
2 1 × 3 3
When you compare the prime factorization of these two numbers, you can see that there are matching prime factors. You can now find the Greatest Common Factor of 129 and 54 by multiplying all the matching prime factors to get a GCF of 129 and 54 as 9:
Thus, the GCF of 129 and 54 is: 9
How to Find the GCF of 129 and 54 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 129 and 54 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, 129 and 54:
Factors of 129: 1, 3, 43, 129
Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54
When you compare the two lists of factors, you can see that the common factor(s) are 1, 3. Since 3 is the largest of these common factors, the GCF of 129 and 54 would be 3.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 110 and 37?
What is the GCF of 149 and 48?
What is the GCF of 90 and 24?
What is the GCF of 32 and 58?
What is the GCF of 133 and 99?