Question

o valor de 2-√2/√2-1 é igual a :

Answer 1

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

Answer 2

 
  

 2-√2 = (2-√2)(√2+1)√2-1      (√2- 1)(√2+1)
2√2 + 2 - √2.2 - √2  =   2√2 + 2 - 2 - √2  ==>  √2
√2.2 + √2 - √2 - 1               2  - 1