(\frac{2}{5}\sqrt8-\sqrt2)^2
źródło:
(\frac{2}{5}\sqrt8-\sqrt2)^2=
Obliczenie dodatkowe
\sqrt8=\sqrt{4*2}=2\sqrt2 …
=(\frac{2}{5}*2\sqrt2-\sqrt2)^2=(\frac{4}{5}\sqrt2-\sqrt2)^2=(\frac{1}{5}\sqrt2)^2=\frac{2}{25}