Question

racionalizando 2-√2 / √2-1 teremos ?

Answer 1

$\dfrac{2- \sqrt{2} }{ \sqrt{2} -1} = \dfrac{(2- \sqrt{2}).(\sqrt{2} +1) }{ (\sqrt{2} -1).(\sqrt{2} +1)} = \dfrac{2\sqrt{2}+2-2-\sqrt{2} }{ 2-1} = \dfrac{\sqrt{2} }{ 1} =\sqrt{2}$