Solution: The GCF of 26 and 84 is 2MethodsHow to find the GCF of 26 and 84 using Prime FactorizationOne way to find the GCF of 26 and 84 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 26?What are the Factors of 84?Here is the prime factorization of 26:21×1312^1 × 13^121×131And this is the prime factorization of 84:22×31×712^2 × 3^1 × 7^122×31×71When 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 26 and 84 by multiplying all the matching prime factors to get a GCF of 26 and 84 as 4:Thus, the GCF of 26 and 84 is: 4How to Find the GCF of 26 and 84 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 26 and 84 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, 26 and 84:Factors of 26: 1, 2, 13, 26Factors of 84: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84When you compare the two lists of factors, you can see that the common factor(s) are 1, 2. Since 2 is the largest of these common factors, the GCF of 26 and 84 would be 2.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 148 and 127?What is the GCF of 10 and 113?What is the GCF of 22 and 91?What is the GCF of 73 and 142?What is the GCF of 45 and 63?