Solution: The GCF of 135 and 90 is 45
Methods
How to find the GCF of 135 and 90 using Prime Factorization
One way to find the GCF of 135 and 90 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 135?
What are the Factors of 90?
Here is the prime factorization of 135:
3
3
×
5
1
3^3 × 5^1
3 3 × 5 1
And this is the prime factorization of 90:
2
1
×
3
2
×
5
1
2^1 × 3^2 × 5^1
2 1 × 3 2 × 5 1
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 135 and 90 by multiplying all the matching prime factors to get a GCF of 135 and 90 as 225:
Thus, the GCF of 135 and 90 is: 225
How to Find the GCF of 135 and 90 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 135 and 90 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, 135 and 90:
Factors of 135: 1, 3, 5, 9, 15, 27, 45, 135
Factors of 90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90
When you compare the two lists of factors, you can see that the common factor(s) are 1, 3, 5, 9, 15, 45. Since 45 is the largest of these common factors, the GCF of 135 and 90 would be 45.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 100 and 126?
What is the GCF of 47 and 127?
What is the GCF of 98 and 44?
What is the GCF of 111 and 136?
What is the GCF of 99 and 132?