63
2 times 3 times 3 times x times y = 18xy
We are missing an important sign (+/-) I shall assume 9x2 - 18xy + 9y2 9(x-y)(x-y)
It is -18xy
y(x - 9)(x - 9)
GCF(18xy, 15xy) = 3xy LCM(18xy, 15xy) = 90xy
2y(x - 5)(x^2 + 9)
72xy
72xy
(3x - y)(3x - 5y) and (2x + 1)(2x + 11)
xy
the GCF is 6y