Because 3 is the largest number that divides into both 12 and 15 evenly with no remainder.
The GCF is 3.
The GCF is 3.
The GCF is 3.
The GCF of 15 and 12 is: 3
The GCF of 9, 12, 15 is 3.
GCF(12, 15, 18) = 3
GCF(15, 12, 45) = 3
3 and 60, respectively.
The GCF of 12 and 15 is 3.
The GCF is 3.
The GCF is 3.
The GCF is 3.