Question 54531
You are really close.
{{{(-3-sqrt(-7))^2}}}
{{{(-3-sqrt(7)i)^2}}}
{{{(-3-sqrt(7)i)(-3-sqrt(7)i)}}}
{{{-3(-3)-3(-sqrt(7)i)-sqrt(7)i(-3)-sqrt(7)i(-sqrt(7)i)}}}
{{{9+3sqrt(7)i+3sqrt(7)i+7i^2}}}  Remember:{{{i^2=-1}}}
{{{9+6sqrt(7)i+7(-1)}}}
{{{9-7+6sqrt(7)i}}}
{{{highlight(2+6sqrt(7)i)}}}
Happy Calculating!!!