a)
[tex]1 \frac{1}{4} - \frac{8}{10} \div \frac{4}{5} = \frac{5}{4} - \frac{8}{10} \times \frac{5}{4} = \frac{5}{4} - \frac{2}{2} \times \frac{1}{1} = \frac{5}{4} - 1 = \frac{1}{4} [/tex]
b)
[tex] \frac{5}{9} - 0.6 \div 1 \frac{4}{5} = \frac{5}{9} - \frac{6}{10} \div \frac{9}{5} = \frac{5}{9} - \frac{6}{10} \times \frac{5}{9} = \frac{5}{9} - \frac{2}{2} \times \frac{1}{3} = \frac{5}{9} - \frac{2}{6} = \frac{10}{18} - \frac{6}{18} = \frac{4}{18} = \frac{2}{9} [/tex]
c)
[tex]2 \frac{2}{3} + 1 \frac{2}{3} \times 0.9 = \frac{8}{3} + \frac{5}{3} \times \frac{9}{10} = \frac{8}{3} + \frac{1}{1} \times \frac{3}{2} = \frac{8}{3} + \frac{3}{2} = \frac{16}{6} + \frac{9}{6} = \frac{25}{6} = 4 \frac{1}{6} [/tex]
Myślę że pomogłem ;)
