We need two more zeroes to make the polynomial degree 5 and to cancel out the two complex zeroes: i and -6-i. So the polynomial becomes (x-i)(x+i)(x+6+i)(x+6-i)(x+3)=(x^2+1)(x^2+12x+37)(x+3)=
(x^3+x+3x^2+3)(x^2+12x+37)=
x^5+12x^4+37x^3+x^3+12x^2+37x+3x^4+36x^3+111x^2+3x^2+36x+111=
x^5+15x^4+74x^3+126x^2+73x+111.