Math Tutor Explains: What is the GCF of 89 and 89?

One way to find the GCF of 89 and 89 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 89?
• What are the Factors of 89?

Here is the prime factorization of 89:

And this is the prime factorization of 89:

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 89 and 89 by multiplying all the matching prime factors to get a GCF of 89 and 89 as 7921:

Thus, the GCF of 89 and 89 is: 7921

The first step to this method of finding the Greatest Common Factor of 89 and 89 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, 89 and 89:

Factors of 89: 1, 89

Factors of 89: 1, 89

When you compare the two lists of factors, you can see that the common factor(s) are 1, 89. Since 89 is the largest of these common factors, the GCF of 89 and 89 would be 89.

Want more practice? Try some of these other GCF problems walkthrough from math tutors:

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