Question

What is the greatest common factor (GCF) of 25 and 35?

Answer 1

The GCF of `25` and `35` is `5`.

Explanation:

One way to find the GCF is to find the prime factorization of each number. So,

`25 = 5^2`
`35 = 5*7`

Now, we can find all the factors `25` and `35` have in common. We see that `25` and `35` both have a `5`, but not `5^2` because `35` only has one `5`.

`35` also has a `7`, but that is not in the prime factorization of `25`, so we do not include it. Since there is only one common factor which is 5, that is our "greatest common factor".