Cześć ;-)
c)
[tex]6\frac{2}{3}\cdot0,25+\frac{1}{5}=\frac{20}{3}\cdot\frac{25}{100}+\frac{1}{5}=\\\\=\frac{\not20^5}{3}\cdot\frac{1}{\not4_1}+\frac{1}{5}=\frac{5}{3}+\frac{1}{5}=\frac{25}{15}+\frac{3}{15}=\frac{28}{15}=1\frac{13}{15}[/tex]
e)
[tex]3\frac{4}{9}-1\frac{2}{3}\cdot1,8=3\frac{4}{9}-\frac{\not5^1}{\not3_1}\cdot\frac{\not18^6}{\not10_2}=\\\\=3\frac{4}{9}-\frac{6}{2}=3\frac{4}{9}-3=\frac{4}{9}[/tex]
Pozdrawiam!