What is GCF for 9 and 13?

2 Answers
Nov 3, 2016

Answer:

GCF of #9# and #13# is #1#.

Explanation:

The factors of #9# are #3xx3#, and

as #13# is a prime number, its only factor is #13#.

Note that there are no common factors between them.

Such numbers are called coprimes or relatively primes.

GCF of such numbers is always #1#.

Nov 4, 2016

Answer:

So GCF (greatest common factor) is 1

Explanation:

Using prime numbers as factors: also including 1

#color(blue)(ul("Very important fact;")" 1 is not a prime numbers")#

#color(brown)("The only factors of a prime number is 1 and the number itself")#

#color(white)(1)9->color(red)(1)xx3xx3#
#13->color(red)(1)color(white)(xx3xx3)xx13color(brown)( larr" Thus 13 is a prime number")#

The only common factor is 1

So GCF (greatest common factor) is 1