What is the gcf of 21 30 anwhat is the gcf of 21, 30, and 44?

Find the prime factorization of each value.

21 is 7*3

30 is 3*10 which can be further broken down into 3*2*5

44 is 4*11 which can be further broken down into 2*2*11

What do they share in common?

21 and 30 each have a 3 in common.

Therefore the GCF (21, 30) = 3.

21 and 44 share a 2 in common.

But if we're looking at all three of them together, they share nothing in common.