Question

1/(1 - √2) - 1/(√2 + 1) é igual a

Answer 1

$\frac{1}{1-\sqrt{2}}-\frac{1}{1+\sqrt{2}}=\\\\\frac{1(1+\sqrt{2})-1(1-\sqrt{2})}{(1-\sqrt{2})(1+\sqrt{2})}=\\\\\frac{1+\sqrt{2}-1+\sqrt{2}}{1-2}=\\\\\frac{2\sqrt{2}}{-1}=\\\\\boxed{-2\sqrt{2}}$