Question

simplifique a expressão abaixo : 

 

   12     

√5-√20 = 

Answer 1

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------                                                                               

Answer 2

$\frac{12}{\sqrt{5} - \sqrt{20}} = \\\\\\ \frac{12}{\sqrt{5} - \sqrt{4 \times 5}} = \\\\\\ \frac{12}{\sqrt{5} - 2\sqrt{5}} = \\\\\\ \frac{12}{- \sqrt{5}} = \\\\\\ - \frac{12}{\sqrt{5}} \times \frac{\sqrt{5}}{\sqrt{5}} = \\\\ \boxed{- \frac{12\sqrt{5}}{5}}$