Oblicz 0,9 : \frac{1}{5} + (\frac{1}{3}-\frac{3}{5})^2
0,9 : \frac{1}{5} + (\frac{1}{3}-\frac{3}{5})^2=
=\frac{9}{\not10^2}\cdot \frac{\not5^1}{1}+(\frac{5}{15}-\frac{9}{15})^2
=\frac{9}{2}+(-\frac{4}{15})^2
=\frac{9}{2}+\frac{16}{225}
=\frac{2025}{450}+\frac{32}{450}
=\frac{2057}{450}=4\frac{257}{450}