Question

What is the greatest common factor of 18 and 45

Answer 1

The prime factorization of 18 is: 2 x 3 x 3.
The prime factorization of 45 is: 3 x 3 x 5.
The prime factors and multiplicities 18 and 45 have in common are: 3 x 3.
3 x 3 is the gcf of 18 and 45.
gcf(18,45) = 9.