2x2y
When you simplify each of those expressions you get 120xy, 210xy and 216xy. The GCF of those is 6xy because it divides evenly into all of them.
The GCF is 6.
The GCF is 9.
The GCF is 4.
The GCF is 30.
50
The GCF is: 1
The GCF is 27.
The GCF is 1.
The GCF is 2.
The GCF is 3.