usun niewymienosc z mianownika -√2 / 3√10 / - kreska ułamkowa

- √2/3√10 = - √2  * √10/3√10 * √10 = -√2 * 10/3 *10 = -√20/30  = -√4 * 5/30 =   = - 2√5/30 = - √5/15

[latex]- frac{sqrt{2}}{3sqrt{10}} =-frac{sqrt{2} cdot sqrt{10}}{3sqrt{10} cdot sqrt{10}}=-frac{sqrt{20}}{3 cdot 10}=-frac{2sqrt{5}}{30}=-frac{sqrt{5}}{15}[/latex]