Szczegółowe wyjaśnienie:
[tex]a)\ \dfrac{3}{\sqrt{15}}=\dfrac{3}{\sqrt{15}}\cdot\dfrac{\sqrt{15}}{\sqrt{15}}=\dfrac{3\!\!\!\!\diagup^1\sqrt{15}}{15\!\!\!\!\!\diagup_5}=\dfrac{\sqrt{15}}{5}\qquad\huge\boxed{TAK}[/tex]
[tex]b)\ \dfrac{4}{\sqrt8}=\dfrac{4}{\sqrt8}\cdot\dfrac{\sqrt8}{\sqrt8}=\dfrac{4\!\!\!\!\diagup^1\sqrt8}{8\!\!\!\!\diagup_2}=\dfrac{\sqrt8}{2}\neq2\sqrt8\qquad\huge\boxed{NIE}[/tex]
[tex]c)\ \dfrac{3}{\sqrt3\cdot\sqrt6}=\dfrac{3}{\sqrt{3\cdot6}}=\dfrac{3}{\sqrt{18}}=\dfrac{3}{\sqrt{9\cdot2}}=\dfrac{3}{\sqrt9\cdot\sqrt2}=\dfrac{3\!\!\!\!\diagup}{3\!\!\!\!\diagup\sqrt2}\\\\=\dfrac{1}{\sqrt2}\cdot\dfrac{\sqrt2}{\sqrt2}=\dfrac{\sqrt2}{2}=\dfrac{1}{2}\sqrt2\qquad\huge\boxed{TAK}[/tex]
