Question: what is the highest common factor between 9 and 36?
Answer: The prime factorization of 36 is: 2 x 2 x 3 x 3. The prime factors and multiplicities 9 and 36 have in common are: 3 x 3. 3 x 3 is the gcf of 9 and 36. gcf(9,36) = 9.