what is the gcf of 15 and 45

To find the greatest common factor (GCF) of 15 and 45, we need to factor each number. The factors of 15 are 1, 3, 5, and 15, while the factors of 45 are 1, 3, 5, 9, 15, and 45. The largest number that is a factor of both 15 and 45 is 15, so the GCF of 15 and 45 is 15.