It is: 1
The GCF is 1.
The GCF is 1.
The GCF of 9 and 10 is 1
The greatest common factor (gcf) of 28 and 36 is 9.
The GCF is 2.
The GCF is 1.
GCF(28, 10) = 2
The GCF of 28 and 63 is 7. This leaves you with 4 and 9 respectively. As there are no more common factors between 4 and 9 aside from 1, the GCF remains 7.
The GCF is 2.
The GCF is 1.
The GCF is 9.
The GCF is 28.