Q:

What is the GCF of 81 and 7?

Accepted Solution

A:
Solution: The GCF of 81 and 7 is 1 Methods How to find the GCF of 81 and 7 using Prime Factorization One way to find the GCF of 81 and 7 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 81? What are the Factors of 7? Here is the prime factorization of 81: 3 4 3^4 3 4 And this is the prime factorization of 7: 7 1 7^1 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 81 and 7 is 1. Thus, the GCF of 81 and 7 is: 1 How to Find the GCF of 81 and 7 by Listing All Common Factors The first step to this method of finding the Greatest Common Factor of 81 and 7 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, 81 and 7: Factors of 81: 1, 3, 9, 27, 81 Factors of 7: 1, 7 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 81 and 7 is 1. Find the GCF of Other Number Pairs Want more practice? Try some of these other GCF problems: What is the GCF of 1 and 53? What is the GCF of 94 and 15? What is the GCF of 105 and 147? What is the GCF of 80 and 72? What is the GCF of 146 and 21?