Question

a=1/√5-2+1/√5+2
aratati ca a e (√19;√20)

Answer 1

A = $\frac{1}{ \sqrt{5} }$ - 2 + $\frac{1}{ \sqrt{5} }$ + 2 
2 si cu 2 se simplifica
A = $\sqrt{ \frac{1}{5} }$ x 2 
A = $\sqrt{ \frac{4}{5} }$
amplifici cu 2 => A = $\sqrt{ \frac{8}{10} }$ =  \sqrt{0,8}