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

1 Answer
Dec 11, 2016

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".