Q:

What is the GCF of 90 and 5?

Accepted Solution

A:
Solution: The GCF of 90 and 5 is 5 Methods How to find the GCF of 90 and 5 using Prime Factorization One way to find the GCF of 90 and 5 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 90? What are the Factors of 5? Here is the prime factorization of 90: 2 1 × 3 2 × 5 1 2^1 × 3^2 × 5^1 2 1 × 3 2 × 5 1 And this is the prime factorization of 5: 5 1 5^1 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 90 and 5 by multiplying all the matching prime factors to get a GCF of 90 and 5 as 25: Thus, the GCF of 90 and 5 is: 25 How to Find the GCF of 90 and 5 by Listing All Common Factors The first step to this method of finding the Greatest Common Factor of 90 and 5 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, 90 and 5: Factors of 90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90 Factors of 5: 1, 5 When you compare the two lists of factors, you can see that the common factor(s) are 1, 5. Since 5 is the largest of these common factors, the GCF of 90 and 5 would be 5. Find the GCF of Other Number Pairs Want more practice? Try some of these other GCF problems: What is the GCF of 113 and 45? What is the GCF of 149 and 131? What is the GCF of 59 and 124? What is the GCF of 86 and 101? What is the GCF of 75 and 54?