GCF = greatet common factor,
the GCF is defined as the largest common factor of given numbers that can divide the numbers completely,
for example, if we have 4 and 6
then the factors
4 = 2 x 2
6 = 2 x 3
so from the above factors, we can see that,
only factor 2 is common and dividing completely 4 and 6
for examples,
20, 50
20 = 2 x 2 x 5 = 2 x 10
50 = 2 x 5 x 5 = 5 x 10
so we have 2 x 5 = 10 is the largest common factor between the factors and it is dividing both the numbers completely,
so GCF = 10
if we take prime numbers,
7 and 11
7 = 1 x 7
11 = 1 x 11
so, we have only factor 1 is common and dividing completely 7 and 11
so, when we have all prime numbers then the GCF will be 1
