gcf of 15,45
The greatest common factor of 15 and 45 is 15 because since 15 is a factor of 45, and 15's largest factor cannot be larger than itself; the gcf of 15 and 45 is 15.
To find the greatest common factor (GCF) of two numbers, you can start by listing out the factors of each number and then identify the largest factor that they have in common.
Let's find the factors of 15:
The factors of 15 are 1, 3, 5, and 15.
Now let's find the factors of 45:
The factors of 45 are 1, 3, 5, 9, 15, and 45.
By comparing the factors of 15 and 45, we can see that they have two factors in common, which are 1 and 15.
Therefore, the greatest common factor (GCF) of 15 and 45 is 15.