2 9*x - 4*y + 4*y - 1
9*x^2 - 4*y + 4*y - 1*1
1*(x + 1/3)*(x - 1/3)
(1*(x + 1/3))*(x - 1/3)
2 -1 + 9*x
-1 + 9*x^2
-1.0 + 9.0*x^2
(1 + 3*x)*(-1 + 3*x)