I'm assuming that that is a quadratic equation:
[tex] x^{2} +3x+3=0[/tex]
The only way to solve this is to use the quadratic formula. When you do that you get a negative number under the square root sign which we all know is illegal, UNLESS you factor out the imaginary "i". So your roots would be this:
[tex]x= \frac{-3+ \sqrt{3}i }{2} ,x= \frac{-3- \sqrt{3}i }{2} [/tex]
