Question 379081
You have overdefined the problem which leaves it not solvable. 
If {{{x=-i}}} is a zero, then so is {{{x=i}}}
{{{f(x)=-3(x-1)(x-2)(x+i)(x-i)}}}
{{{f(x)=-3(x^2-3x+2)(x^2+1)}}}
However,
{{{f(0)=-3(2)(1)=-6}}} and does not equal {{{8}}}.
So there is no solution.