2. Сложение и вычитание смешанных чисел с разными знаменателями

1) $9\frac{3}{4} + 3\frac{1}{6} = 9\frac{9}{12} + 3\frac{2}{12} = 12\frac{11}{12}$ 2) $7\frac{8}{9} - 2\frac{2}{3} = 7\frac{8}{9} - 2\frac{6}{9} = 5\frac{2}{9}$ 3) $11\frac{7}{12} + 6\frac{11}{18} = 11\frac{21}{36} + 6\frac{22}{36} = 17\frac{43}{36} = 18\frac{7}{36}$ 4) $5\frac{5}{9} - 2\frac{4}{7} = 5\frac{35}{63} - 2\frac{36}{63} = 4\frac{98}{63} - 2\frac{36}{63} = 2\frac{62}{63}$ 5) $9 - 2\frac{3}{7} = 8\frac{7}{7} - 2\frac{3}{7} = 6\frac{4}{7}$ 6) $7\frac{5}{16} + 4\frac{1}{6} + 3\frac{3}{8} = 7\frac{15}{48} + 4\frac{8}{48} + 3\frac{18}{48} = 14\frac{41}{48}$ 7) $8\frac{5}{9} + 7\frac{3}{4} + 12\frac{7}{12} = 8\frac{20}{36} + 7\frac{27}{36} + 12\frac{21}{36} = 27\frac{68}{36} = 27 + 1\frac{32}{36} = 28\frac{8}{9}$ 8) $6\frac{7}{8} - 3\frac{1}{3} + 5\frac{5}{16} = 6\frac{21}{24} - 3\frac{8}{24} + 5\frac{5}{16} = 3\frac{13}{24} + 5\frac{5}{16} = 3\frac{26}{48} + 5\frac{15}{48} = 8\frac{41}{48}$ 9) $5\frac{8}{15} + 4\frac{7}{12} - 3\frac{19}{20} = 5\frac{32}{60} + 4\frac{35}{60} - 3\frac{57}{60} = 9\frac{67}{60} - 3\frac{57}{60} = 6\frac{10}{60} = 6\frac{1}{6}$ 10) $5\frac{9}{14} - 2\frac{3}{7} + 6,7 = 5\frac{9}{14} - 2\frac{6}{14} + 6\frac{7}{10} = 3\frac{3}{14} + 6\frac{7}{10} = 3\frac{15}{70} + 6\frac{49}{70} = 9\frac{64}{70} = 9\frac{32}{35}$