soluzione
Scomporre
x
3
- 5x
2
+ 6x - 2x
2
y + 12xy - 18y =
= x(x
2
- 5x + 6) - 2y(x
2
- 6x + 9) =
= x(x - 2)(x - 3)) - 2y(x - 3)
2
=
= (x - 3)[x(x-2) - 2y(x-3)] =
= (x - 3)(x
2
- 2x - 2xy + 6y)