Question 898350
You most likely know how to square a binomial.


{{{((-4)-sqrt(-5))^2}}}
{{{(-4)^2-(-4)sqrt(-5)-(-4)sqrt(-5)+(-5)}}}
{{{16+4sqrt(-5)+4sqrt(-5)-5}}}
{{{8sqrt(-5)+11}}}
{{{11+8sqrt(-5)}}}, or to use {{{i^2=-1}}},
{{{highlight(11+8i*sqrt(5))}}}