Вычислите значения выражений: 1). 7/15 : (6/10 - 8/3) + 19 * 2/31; 2). (1 1/35 : 4/5 - 1 8/35) * 3 1/3; 3). 2 7/9 * 18/25 + 9/60 : (7/12 - 3/5); 4). (4/5 + 4/7) * (3 3/8 + 2 11/4); 5). -3 1/7 * (-8) - 2,9 : 0,1 + 11/21 : (-3 2/3); 6). (6 - 2 4/5) * 3 1/8 - 1 3/5 : 1/4; 7). 4 1/6 * (1 2/5 - 3/5) + (3/4 + 5/6) * 6; 8). 7 * 2 6/7 + 53/12 : (7/9 - 9/4)

1). $\frac{7}{15} : (\frac{6}{10} - \frac{8}{3}) + 19 \cdot \frac{2}{31} = \frac{7}{15} : (\frac{18 - 80}{30}) + \frac{38}{31} = \frac{7}{15} : (-\frac{62}{30}) + \frac{38}{31} = \frac{7}{15} \cdot (-\frac{30}{62}) + \frac{38}{31} = -\frac{7 \cdot 2}{62} + \frac{38}{31} = -\frac{7}{31} + \frac{38}{31} = \frac{31}{31} = 1$. **Ответ: 1.** 2). $(1\frac{1}{35} : \frac{4}{5} - 1\frac{8}{35}) \cdot 3\frac{1}{3} = (\frac{36}{35} \cdot \frac{5}{4} - \frac{43}{35}) \cdot \frac{10}{3} = (\frac{9}{7} - \frac{43}{35}) \cdot \frac{10}{3} = (\frac{45 - 43}{35}) \cdot \frac{10}{3} = \frac{2}{35} \cdot \frac{10}{3} = \frac{2 \cdot 2}{7 \cdot 3} = \frac{4}{21}$. **Ответ: 4/21.** 3). $2\frac{7}{9} \cdot \frac{18}{25} + \frac{9}{60} : (\frac{7}{12} - \frac{3}{5}) = \frac{25}{9} \cdot \frac{18}{25} + \frac{3}{20} : (\frac{35 - 36}{60}) = 2 + \frac{3}{20} : (-\frac{1}{60}) = 2 + \frac{3}{20} \cdot (-60) = 2 - 9 = -7$. **Ответ: -7.** 4). $(\frac{4}{5} + \frac{4}{7}) \cdot (3\frac{3}{8} + 2\frac{11}{4}) = (\frac{28 + 20}{35}) \cdot (\frac{27}{8} + \frac{19}{4}) = \frac{48}{35} \cdot (\frac{27 + 38}{8}) = \frac{48}{35} \cdot \frac{65}{8} = \frac{6 \cdot 13}{7} = \frac{78}{7} = 11\frac{1}{7}$. **Ответ: 11 1/7.** 5). $-3\frac{1}{7} \cdot (-8) - 2,9 : 0,1 + \frac{11}{21} : (-3\frac{2}{3}) = -\frac{22}{7} \cdot (-8) - 29 + \frac{11}{21} : (-\frac{11}{3}) = \frac{176}{7} - 29 - \frac{11}{21} \cdot \frac{3}{11} = 25\frac{1}{7} - 29 - \frac{1}{7} = 25 - 29 = -4$. **Ответ: -4.** 6). (6 - 2\frac{4}{5}) \cdot 3\frac{1}{8} - 1\frac{3}{5} : \frac{1}{4} = 3\frac{1}{5} \cdot \frac{25}{8} - \frac{8}{5} \cdot 4 = \frac{16}{5} \cdot \frac{25}{8} - \frac{32}{5} = 10 - 6,4 = 3,6$. **Ответ: 3,6.** 7). 4\frac{1}{6} \cdot (1\frac{2}{5} - \frac{3}{5}) + (\frac{3}{4} + \frac{5}{6}) \cdot 6 = \frac{25}{6} \cdot \frac{4}{5} + (\frac{9 + 10}{12}) \cdot 6 = \frac{5 \cdot 2}{3} + \frac{19}{12} \cdot 6 = \frac{10}{3} + \frac{19}{2} = 3\frac{1}{3} + 9\frac{1}{2} = 3\frac{2}{6} + 9\frac{3}{6} = 12\frac{5}{6}$. **Ответ: 12 5/6.** 8). 7 \cdot 2\frac{6}{7} + \frac{53}{12} : (\frac{7}{9} - \frac{9}{4}) = 7 \cdot \frac{20}{7} + \frac{53}{12} : (\frac{28 - 81}{36}) = 20 + \frac{53}{12} : (-\frac{53}{36}) = 20 - \frac{53}{12} \cdot \frac{36}{53} = 20 - 3 = 17$. **Ответ: 17.**