Because 4 is the largest positive integer that divides evenly into both 28 and 72 with no remainder.
The GCF is 4.
The GCF of 28, 68, 72 is 4.
The greatest common factor of 28 and 72 is 4.
The GCF is 4.
The GCF is 4.
The GCF is 4.
The GCF is 4.
The GCF is 4.
The GCF is 4.
4
The GCF of 28, 68, 72 is 4.
The greatest common factor of 28 and 72 is 4.
The GCF is 4.
The GCF is 4.
GCF(72, 44) = 4.
The greatest common factor (GCF) of 68 and 72 is 4.
The GCF is 4.