2 2 16*x - 144*y
16*x^2 - 144*y^2
1*(x + 3*y)*(x - 3*y)
(1*(x + 3*y))*(x - 3*y)
16*(x - 3*y)*(x + 3*y)
16.0*x^2 - 144.0*y^2
/ 2 2\ 16*\x - 9*y /
16*(x^2 - 9*y^2)