2. Найдите значение выражения: a) $$(8 - 2 \cdot 3 \frac{1}{7}) \div \frac{1}{9}$$; б) $$4 \frac{4}{5} + \frac{4}{7} \cdot (7 \frac{11}{12} - 5 \frac{7}{9})$$; r) $$4 \frac{2}{3} \cdot 6 - 1 \frac{23}{42} \div \frac{8}{3 \cdot 1 \frac{1}{2} + 2 \cdot 1 \frac{1}{4}}$$; д) $$(\frac{5}{10} - 3 \frac{3}{5}) \cdot \frac{4}{13} \cdot (5 \frac{1}{16} - 1) \div (5 + 3 \frac{5}{6} \cdot \frac{3}{14})$$; e) $$\frac{19}{24} \div \frac{7}{12} + (3 \frac{1}{8} \div \frac{3}{8}) \cdot (- \frac{1}{48})$$; ж) $$(\frac{15}{16} \div 12 + 2 \frac{1}{2}) \cdot \frac{5}{4}$$; з) $$3 \frac{3}{4} \div 1 \frac{1}{5} + 1 \frac{3}{5} \div 1 \frac{1}{2}$$; и) $$(8 - 7 \frac{13}{17}) \cdot (2 \frac{1}{4} + 3 \frac{3}{4}) \div 2$$; к) $$5 \frac{4}{9} \div (2 \frac{1}{3})^2 \cdot 1 \frac{3}{4} \div \frac{8 \cdot 1}{20} + 12 \frac{3}{4}$$; л) $$(1 \frac{1}{2})^3 \div 4 \frac{1}{6} \cdot 8 \cdot (1 \frac{1}{2})^2 - 12 \frac{2}{5} \cdot 0.8 \div \frac{3}{4} + 2 \frac{5}{9} \cdot 7 \frac{1}{7}$$.

a) $$(8 - 2 \cdot 3 \frac{1}{7}) \div \frac{1}{9} = (8 - \frac{2 \cdot 22}{7}) \cdot 9 = (8 - \frac{44}{7}) \cdot 9 = (\frac{56 - 44}{7}) \cdot 9 = \frac{12}{7} \cdot 9 = \frac{108}{7} = 15 \frac{3}{7}$$

б) $$4 \frac{4}{5} + \frac{4}{7} \cdot (7 \frac{11}{12} - 5 \frac{7}{9}) = \frac{24}{5} + \frac{4}{7} \cdot (\frac{95}{12} - \frac{52}{9}) = \frac{24}{5} + \frac{4}{7} \cdot (\frac{95 \cdot 3 - 52 \cdot 4}{36}) = \frac{24}{5} + \frac{4}{7} \cdot (\frac{285 - 208}{36}) = \frac{24}{5} + \frac{4}{7} \cdot \frac{77}{36} = \frac{24}{5} + \frac{4 \cdot 11}{36} = \frac{24}{5} + \frac{11}{9} = \frac{24 \cdot 9 + 11 \cdot 5}{45} = \frac{216 + 55}{45} = \frac{271}{45} = 6 \frac{1}{45}$$

г) $$4 \frac{2}{3} \cdot 6 - 1 \frac{23}{42} \div \frac{8}{3 \cdot 1 \frac{1}{2} + 2 \cdot 1 \frac{1}{4}} = \frac{14}{3} \cdot 6 - \frac{65}{42} \div \frac{8}{3 \cdot \frac{3}{2} + 2 \cdot \frac{5}{4}} = 28 - \frac{65}{42} \div \frac{8}{\frac{9}{2} + \frac{5}{2}} = 28 - \frac{65}{42} \div \frac{8}{7} = 28 - \frac{65 \cdot 7}{42 \cdot 8} = 28 - \frac{65}{6 \cdot 8} = 28 - \frac{65}{48} = \frac{28 \cdot 48 - 65}{48} = \frac{1344 - 65}{48} = \frac{1279}{48} = 26 \frac{31}{48}$$

д) $$(\frac{5}{10} - 3 \frac{3}{5}) \cdot \frac{4}{13} \cdot (5 \frac{1}{16} - 1) \div (5 + 3 \frac{5}{6} \cdot \frac{3}{14}) = (\frac{1}{2} - \frac{18}{5}) \cdot \frac{4}{13} \cdot (\frac{81}{16} - 1) \div (5 + \frac{23}{6} \cdot \frac{3}{14}) = (\frac{5 - 36}{10}) \cdot \frac{4}{13} \cdot \frac{65}{16} \div (5 + \frac{23}{28}) = -\frac{31}{10} \cdot \frac{4}{13} \cdot \frac{65}{16} \div \frac{140 + 23}{28} = -\frac{31 \cdot 4 \cdot 65 \cdot 28}{10 \cdot 13 \cdot 16 \cdot 163} = -\frac{31 \cdot 2 \cdot 5 \cdot 13 \cdot 4 \cdot 7}{2 \cdot 5 \cdot 13 \cdot 4 \cdot 4 \cdot 163} = -\frac{31 \cdot 7}{2 \cdot 163} = -\frac{217}{326}$$

e) $$\frac{19}{24} \div \frac{7}{12} + (3 \frac{1}{8} \div \frac{3}{8}) \cdot (- \frac{1}{48}) = \frac{19}{24} \cdot \frac{12}{7} + (\frac{25}{8} \cdot \frac{8}{3}) \cdot (- \frac{1}{48}) = \frac{19}{2 \cdot 7} + \frac{25}{3} \cdot (- \frac{1}{48}) = \frac{19}{14} - \frac{25}{144} = \frac{19 \cdot 72 - 25 \cdot 7}{14 \cdot 72} = \frac{1368 - 175}{1008} = \frac{1193}{1008} = 1 \frac{185}{1008}$$

ж) $$(\frac{15}{16} \div 12 + 2 \frac{1}{2}) \cdot \frac{5}{4} = (\frac{15}{16 \cdot 12} + \frac{5}{2}) \cdot \frac{5}{4} = (\frac{5}{16 \cdot 4} + \frac{5}{2}) \cdot \frac{5}{4} = (\frac{5}{64} + \frac{5 \cdot 32}{2 \cdot 32}) \cdot \frac{5}{4} = (\frac{5}{64} + \frac{160}{64}) \cdot \frac{5}{4} = \frac{165}{64} \cdot \frac{5}{4} = \frac{825}{256} = 3 \frac{57}{256}$$

з) $$3 \frac{3}{4} \div 1 \frac{1}{5} + 1 \frac{3}{5} \div 1 \frac{1}{2} = \frac{15}{4} \div \frac{6}{5} + \frac{8}{5} \div \frac{3}{2} = \frac{15 \cdot 5}{4 \cdot 6} + \frac{8 \cdot 2}{5 \cdot 3} = \frac{75}{24} + \frac{16}{15} = \frac{25}{8} + \frac{16}{15} = \frac{25 \cdot 15 + 16 \cdot 8}{8 \cdot 15} = \frac{375 + 128}{120} = \frac{503}{120} = 4 \frac{23}{120}$$

и) $$(8 - 7 \frac{13}{17}) \cdot (2 \frac{1}{4} + 3 \frac{3}{4}) \div 2 = (8 - \frac{132}{17}) \cdot (\frac{9}{4} + \frac{15}{4}) \div 2 = (\frac{136 - 132}{17}) \cdot \frac{24}{4} \div 2 = \frac{4}{17} \cdot 6 \div 2 = \frac{4 \cdot 6}{17 \cdot 2} = \frac{24}{34} = \frac{12}{17}$$

к) $$5 \frac{4}{9} \div (2 \frac{1}{3})^2 \cdot 1 \frac{3}{4} \div \frac{8 \cdot 1}{20} + 12 \frac{3}{4} = \frac{49}{9} \div (\frac{7}{3})^2 \cdot \frac{7}{4} \div \frac{8}{20} + \frac{51}{4} = \frac{49}{9} \div \frac{49}{9} \cdot \frac{7}{4} \div \frac{2}{5} + \frac{51}{4} = 1 \cdot \frac{7}{4} \cdot \frac{5}{2} + \frac{51}{4} = \frac{35}{8} + \frac{51}{4} = \frac{35 + 102}{8} = \frac{137}{8} = 17 \frac{1}{8}$$

л) $$(1 \frac{1}{2})^3 \div 4 \frac{1}{6} \cdot 8 \cdot (1 \frac{1}{2})^2 - 12 \frac{2}{5} \cdot 0.8 \div \frac{3}{4} + 2 \frac{5}{9} \cdot 7 \frac{1}{7} = (\frac{3}{2})^3 \div \frac{25}{6} \cdot 8 \cdot (\frac{3}{2})^2 - \frac{62}{5} \cdot \frac{4}{5} \div \frac{3}{4} + \frac{23}{9} \cdot \frac{50}{7} = \frac{27}{8} \div \frac{25}{6} \cdot 8 \cdot \frac{9}{4} - \frac{248}{25} \div \frac{3}{4} + \frac{1150}{63} = \frac{27 \cdot 6 \cdot 8 \cdot 9}{8 \cdot 25 \cdot 4} - \frac{248 \cdot 4}{25 \cdot 3} + \frac{1150}{63} = \frac{27 \cdot 6 \cdot 9}{25 \cdot 4} - \frac{992}{75} + \frac{1150}{63} = \frac{1458}{100} - \frac{992}{75} + \frac{1150}{63} = \frac{729}{50} - \frac{992}{75} + \frac{1150}{63} = \frac{729 \cdot 189 - 992 \cdot 42 + 1150 \cdot 50}{50 \cdot 189} = \frac{137781 - 41664 + 57500}{9450} = \frac{153617}{9450} = 16 \frac{2017}{9450}$$

Ответ: a) $$15 \frac{3}{7}$$; б) $$6 \frac{1}{45}$$; г) $$26 \frac{31}{48}$$; д) $$-\frac{217}{326}$$; e) $$1 \frac{185}{1008}$$; ж) $$3 \frac{57}{256}$$; з) $$4 \frac{23}{120}$$; и) $$\frac{12}{17}$$; к) $$17 \frac{1}{8}$$; л) $$16 \frac{2017}{9450}$$