What is the GCF of 13 and 7? Is it: 91, 1, 13, or 7 ??
2006-10-23 06:09:31 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
13 and 7 are both prime numbers, so the GCF is 1.
91 is the least common multiple (LCM) of 13 and 7.
2006-10-23 06:10:57 · answer #1 · answered by James L 5 · 0⤊ 0⤋
Factor each number first to figure out the GCF.
If you remember with your factoring, go through each prime number and see if it is a factor. As an example, keep in mind that 30 can be factored into 2 * 3 * 5 and that 12 can be factored into 2 * 2 * 3. You don't need to include 1 and the number itself as factors.
To figure out the CGF, you match up the factors and multiply them together. For the example of 30 and 12, you can see that the two numbers have 2 and 3 in common. 2 * 3 = 6, so 6 is the GCF.
Do the same thing with 7 and 13. Look at the factors. You can find out that:
7 = 1 * 7
13 = 1 * 13
(as I said above, you don't need to look at 1 and the number, but I branched out here so you can see where I'm going)
The only factor they have in common is 1. So, the LCF of 7 and 13 is 1.
As you learn more about prime numbers and can list off all of the prime numbers under 30, you'll be able to recognize primes more easily. With experience, you can see that 7 and 13 are both prime, so you don't need to factor to figure out that the GCF is 1. You just know that the two prime numbers don't have any other factors.
2006-10-23 06:12:40 · answer #2 · answered by Rev Kev 5 · 1⤊ 0⤋
1
2006-10-23 07:40:52 · answer #3 · answered by logesn 1 · 0⤊ 0⤋
You are wanting to find what common number can both of 39 and 26 be divided. In this case, it will be 13. Usually you can use 2, 2 and so on and then just multiply them altogether. However, you can't do that for this question. So just keep trying and you'll find that the only common number both 39 and 26 can be divided by is 13. This will give you a remainder of 3 and 2 respectively and there are no more common number for 3 and 2.
2016-03-28 05:05:19 · answer #4 · answered by Anonymous · 0⤊ 0⤋
It's 1 because 13 and 7 are both prime numbers.
2006-10-23 06:12:45 · answer #5 · answered by steiner1745 7 · 0⤊ 0⤋
factors of 7 are : 1,7 (because it's a prime number)
facttors of 13 are:1,13 (~)
so GCF(7,13)=1
in general GCF of a prime number to any other number is 1 unless that other number is a multiplicantion of that prime number
for exampe GCF(7,a) is 1 unless a=7,14,21,28,.... inthat case GCF = 7
;)
2006-10-23 06:14:12 · answer #6 · answered by Farshad Gh 2 · 0⤊ 0⤋
the anwser is 1
not 91, 13, or 7
2006-10-23 06:12:49 · answer #7 · answered by Oo蒹葭oO 1 · 0⤊ 0⤋
Common factor? 1
LCM? 91
2006-10-23 07:10:58 · answer #8 · answered by yupchagee 7 · 0⤊ 0⤋
it is 1 as they are prime to each other,that is do not have any common factor
2006-10-23 06:11:06 · answer #9 · answered by raj 7 · 0⤊ 0⤋