Respuesta :
X=1 has to give -6. Only 3x3-3x2-6x satisfies that: 3-3-6=-6; No need to anything else! Wow ... Usually there are two options left and one needs to do something else.
the other ones pass through (1,-2); (1,0) and (1,0)
the other ones pass through (1,-2); (1,0) and (1,0)