Zero is nothing, zip, zilch, nil, nada. It doesn't have any factors so it can't have any in common.
The GCF is 45.
The GCF of 45 and 50 is 5.The GCF is 5.
The GCF is 45.
The GCF is 45.
The GCF is 5.
The GCF is 1.
The GCF is: 5
The GCF is 15.
The GCF is 45.
The GCF is 1.
The GCF is 9.
The GCF is 45.