Respostas

  • Usuário do Brainly
2013-05-28T20:50:15-03:00

Temos que:

 

\dfrac{2+\sqrt{3}}{1-\sqrt{5}}+\dfrac{2-\sqrt{3}}{1-\sqrt{5}}

 

Desta maneira:

 

=\dfrac{(2+\sqrt{3})\cdot(1+\sqrt{5})+(2-\sqrt{3})\cdot(1-\sqrt{5})}{(1-\sqrt{5})\cdot(1+\sqrt{5})}

 

=\dfrac{2+\sqrt{3}+2\sqrt{5}+\sqrt{15}+2-2\sqrt{5}-\sqrt{3}+\sqrt{15}}{1^2-(\sqrt{5})^2}

 

=\dfrac{4}{-4}=-1