Question 836083
Use the FOIL method,
{{{(sqrt(13)-sqrt(2))(sqrt(13)-sqrt(2))=sqrt(13)sqrt(13)-sqrt(13)sqrt(2)-sqrt(2)sqrt(13)+sqrt(2)sqrt(2)}}}
{{{(sqrt(13)-sqrt(2))(sqrt(13)-sqrt(2))=13-2*sqrt(13)sqrt(2)+2}}}
{{{(sqrt(13)-sqrt(2))(sqrt(13)-sqrt(2))=15-2*sqrt(13)sqrt(2)}}}