Question

How do you find the GCF of 98 and 28?

Answer 1

Hint: The GCF is the greatest common factor that means GCF of 2 or more numbers is the greatest number which is a factor of all the numbers given. We can find the GCF of 2 numbers by writing all the numbers as the product of their prime factors, then we can take all the common factors and their product will be GCF. For example a=$3\times 3\times 3$ and b=$3\times 3$ then common factors are 3 and 3. There are two 3 in common so the GCF is 9.

Complete step by step answer:
We have to find the GCF of 98 and 28
To find GCF of above 2 numbers let’s write the numbers as a product of their prime factors and then take all the common factors out.
So we can write 98 as $2\times 7\times 7$
We can write 28 as $2\times 2\times 7$
We can the common factors are one 2 and one 7 so the GCF of 98 and 28 is $2\times 7=14$
This is one way we can find the GCF.

Note:
If GCF of 2 numbers is 1 then we call the 2 numbers as co-prime. Given 2 integers the product of LCM and GCF of 2 numbers is always equal to the product of the 2 numbers whose LCM is the lowest common multiple of the numbers. So if LCM is given and a product of 2 numbers is given then GCF will be a product divided by LCM.