what is the gcf of 12 and 15 and how do you do it

Question

zarkon · Answer

you could look at the prime factorization of each number

anonymous · Answer

???

anonymous · Answer

You can also use euclid's algorithm: for 2 positive integers m and n, m >= n
1. Find the remainder of m / n:
- If it is zero, then n is the gcd of m and n.
- Otherwise, set n to m and set the remainder to n, and repeat step 1.

anonymous · Answer

after one iteration you will find that the gcd is 3

anonymous · Answer

;0 way to hard

zarkon · Answer

actually that is the best way to do it

karatechopper · Answer

i always find the gcf by primefactorization or if u dont kno how to do tht u can list them like this
12:
15:
in this case when u list them:
12:1,12,2,6,3,4
15:1,15,3,5
GCF means Greatest Common Factor
Greatest is the largest
the common factors of 12 and 15 are 1 and 3
the Greatest factor is 3
therefore the GCF of 12 and 15 is 3

zarkon · Answer

but I figured you would want to work with primes though

karatechopper · Answer

do u understand what i said cooljhonny911?

anonymous · Answer

not realy

anonymous · Answer

prime factorization is the easiest way:

15 has prime factors 3*5
12 has prime factors 2*2*3

it's quite clear that 3 is the greatest common factor of the two

anonymous · Answer

Here are some videos that will help: http://www.youtube.com/watch?v=3eyjE-FN4Tw http://www.youtube.com/watch?v=3jGAcpK2V7Q