Question: what is the greatest common factor between 49 and 9?
Answer: The prime factorization of 9 is: 3 x 3.
The prime factorization of 49 is: 7 x 7.
The prime factors and multiplicities 9 and 49 have in common are: 1.
1 is the gcf of 9 and 49.
gcf(9,49) = 1.