answer
[tex]\sqrt{11} - \sqrt{31}[/tex]i
explanation
note that i = [tex]\sqrt{-1}[/tex] and that [tex]\sqrt{ab} =\sqrt{a} *\sqrt{b}[/tex]
[tex]\sqrt{11} - \sqrt{-31}[/tex]
= [tex]\sqrt{11} - \sqrt{31 * -1}[/tex]
= [tex]\sqrt{11} - \sqrt{31}*\sqrt{-1}[/tex]
= [tex]\sqrt{11} - \sqrt{31}[/tex]i
note that the i is outside of the square root
