You have one of the zeros, 1-sqrt(3)i. Since they always come in groups, (some theorem i forgot that states if (a+bi) is an factor, then (a-bi) is also one) then another zero is 1+sqrt(3)i. Then you times them together and use long division with the answer you just got and 3x^3-4x^2+8x+8 to get the answer.