Question: what is the prime factorization of 12 and 45?
Answer: The prime factorization of 12 is: 2 x 2 x 3. The prime factorization of 45 is: 3 x 3 x 5. The prime factors and multiplicities 12 and 45 have in common are: 3. 3 is the gcf of 12 and 45.