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.
x3y2 + 7x2y3 + 7xy - 2 + x2y3 + 8x3y2 - 3xy - 7 =9x3y2 + 8x2y3 + 4xy - 9 =xy ( 9x2y + 8xy2 + 4) - 9 =xy ( xy(9x + 8y) + 4) - 9 .This is still messy, but it's simpler than the octonomial in the question,and we can't see any more that can be done with it.
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.