The GCF is 21.
The GCF is 7.
The GCF is 21.
GCF(42, 63, 84) = 21.
The GCF is 21.
The GCF is 21.
The GCF is 21.
The GCF is 21.
The GCF is 21.
The GCF of 28, 42 and 63 is 7.The GCF is 7.
The GCF of 21 and 42 is 21. The GCF of 17 and 27 is 1.
The GCF is 7.