1) 5 7\8 - 2 2\3 + 4 5\6 2) 8 5\7 + 4 3\4 - 3 5\8 3) 6 8\15 + 4 5\18 - 3,6 4) (31 - 14...

№1
$5 \frac{7}{8} - 2 \frac{2}{3} +4 \frac{5}{6} = \frac{47}{8} - \frac{8}{3} + \frac{29}{6} = \frac{141}{24} - \frac{64}{24} + \frac{116}{24} = \frac{193}{24} = 8 \frac{1}{24}$
№2
$8\frac{5}{7} + 4\frac{3}{4} - 3\frac{5}{8} = \frac{61}{7} + \frac{19}{4} - \frac{29}{8} = \ \textgreater \ \frac{244}{28} + \frac{133}{28} = \frac{377}{28}$
$\frac{377}{28} - \frac{29}{8} = \frac{3016}{224} - \frac{812}{224} = \frac{2204}{224}= 9\frac{188}{224} = 9\frac{47}{56}$
№3
$6\frac{8}{15} + 4\frac{5}{18} - 3\frac{6}{10} = \frac{98}{15} + \frac{79}{18} - \frac{36}{10}= \frac{588}{90} + \frac{395}{90} - \frac{324}{90} = \frac{659}{90}= 7\frac{29}{90}$
№4
$(31-14 \frac{7}{15})-( 27\frac{2}{5} - 19\frac{3}{4})= (31-\frac{217}{15})-( \frac{137}{5}- \frac{79}{4})$
$= (\frac{465}{15} - \frac{217}{15})-( \frac{548}{20}- \frac{395}{20})= \frac{248}{15} - \frac{153}{20}= \frac{992}{60} - \frac{459}{60}= \frac{533}{60}= 8\frac{53}{60}$
№5
$(43 \frac{7}{18} - 5\frac{2}{9})- 12\frac{8}{27} = (\frac{774}{18} - \frac{47}{9})- \frac{324}{27}= (\frac{774}{18} - \frac{94}{18})- \frac{324}{27}= \frac{680}{18}- \frac{324}{27}$ $= \frac{2040}{54} - \frac{648}{54} = \frac{1392}{54} = 25\frac{42}{54}$