Question 964445
Not a possible polynomial. 
It has degree three which means it has 3 roots. 
Two roots are real. 
One root is complex but it has real coefficients.
A polynomial with real coefficients must have complex roots in complex conjugate pairs or else the coefficients will be complex. 
So something is wrong with the problem setup? 
If the degree was 4, you could add {{{x=i}}} as the complex conjugate root. 
Check the problem setup and repost if needed.