Solution: The GCF of 59 and 18 is 1
Methods
How to find the GCF of 59 and 18 using Prime Factorization
One way to find the GCF of 59 and 18 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 59?
What are the Factors of 18?
Here is the prime factorization of 59:
5
9
1
59^1
5 9 1
And this is the prime factorization of 18:
2
1
×
3
2
2^1 × 3^2
2 1 × 3 2
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 59 and 18 is 1.
Thus, the GCF of 59 and 18 is: 1
How to Find the GCF of 59 and 18 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 59 and 18 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, 59 and 18:
Factors of 59: 1, 59
Factors of 18: 1, 2, 3, 6, 9, 18
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 59 and 18 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 87 and 95?
What is the GCF of 40 and 45?
What is the GCF of 146 and 19?
What is the GCF of 92 and 149?
What is the GCF of 63 and 143?