Помоги решить примеры 31-64 с дробями

31. $$\frac{12}{25} \cdot \frac{5}{16} = \frac{12 \cdot 5}{25 \cdot 16} = \frac{3 \cdot 1}{5 \cdot 4} = \frac{3}{20}$$ 32. $$1\frac{3}{4} \cdot 1\frac{3}{7} = \frac{7}{4} \cdot \frac{10}{7} = \frac{1 \cdot 5}{2 \cdot 1} = \frac{5}{2} = 2\frac{1}{2}$$ 33. $$2\frac{2}{3} \cdot 3\frac{3}{4} = \frac{8}{3} \cdot \frac{15}{4} = \frac{2 \cdot 5}{1 \cdot 1} = 10$$ 34. $$15\frac{7}{8} \cdot 1\frac{1}{7} = \frac{127}{8} \cdot \frac{8}{7} = \frac{127 \cdot 1}{1 \cdot 7} = \frac{127}{7} = 18\frac{1}{7}$$ 35. $$0 \cdot 12\frac{3}{5} = 0$$ 36. $$2\frac{1}{2} \cdot 4\frac{2}{15} = \frac{5}{2} \cdot \frac{62}{15} = \frac{1 \cdot 31}{1 \cdot 3} = \frac{31}{3} = 10\frac{1}{3}$$ 37. $$(\frac{5}{12} + \frac{3}{8}) \cdot \frac{6}{19} = (\frac{10}{24} + \frac{9}{24}) \cdot \frac{6}{19} = \frac{19}{24} \cdot \frac{6}{19} = \frac{1}{4} \cdot \frac{1}{1} = \frac{1}{4}$$ 38. $$(3\frac{1}{2} - 2\frac{3}{4}) \cdot (1\frac{1}{6} - \frac{1}{12}) = (\frac{7}{2} - \frac{11}{4}) \cdot (\frac{7}{6} - \frac{1}{12}) = (\frac{14}{4} - \frac{11}{4}) \cdot (\frac{14}{12} - \frac{1}{12}) = \frac{3}{4} \cdot \frac{13}{12} = \frac{1 \cdot 13}{4 \cdot 4} = \frac{13}{16}$$ 39. $$2\frac{2}{3} \cdot \frac{9}{16} - \frac{7}{24} \cdot 2 = \frac{8}{3} \cdot \frac{9}{16} - \frac{7}{24} \cdot \frac{2}{1} = \frac{1 \cdot 3}{1 \cdot 2} - \frac{7 \cdot 1}{12 \cdot 1} = \frac{3}{2} - \frac{7}{12} = \frac{18}{12} - \frac{7}{12} = \frac{11}{12}$$ 40. $$6\frac{6}{7} \cdot (\frac{11}{18} - \frac{5}{12}) = \frac{48}{7} \cdot (\frac{22}{36} - \frac{15}{36}) = \frac{48}{7} \cdot \frac{7}{36} = \frac{4 \cdot 1}{1 \cdot 3} = \frac{4}{3} = 1\frac{1}{3}$$ 41. $$8\frac{3}{5} - 3\frac{15}{27} = \frac{43}{5} - \frac{96}{27} = \frac{43}{5} - \frac{32}{9} = \frac{387}{45} - \frac{160}{45} = \frac{227}{45} = 5 \frac{2}{45}$$ 42. $$\frac{3}{12} : \frac{3}{4} = \frac{3}{12} \cdot \frac{4}{3} = \frac{1 \cdot 1}{3 \cdot 1} = \frac{1}{3}$$ 43. $$\frac{4}{5} : \frac{8}{25} = \frac{4}{5} \cdot \frac{25}{8} = \frac{1 \cdot 5}{1 \cdot 2} = \frac{5}{2} = 2\frac{1}{2}$$ 44. $$8 : \frac{2}{7} = \frac{8}{1} \cdot \frac{7}{2} = \frac{4 \cdot 7}{1 \cdot 1} = 28$$ 45. $$1 : \frac{3}{17} = \frac{1}{1} \cdot \frac{17}{3} = \frac{17}{3} = 5\frac{2}{3}$$ 46. $$0 : 5\frac{1}{19} = 0$$ 47. $$0 - 5,6 = -5,6$$ 48. $$(5\frac{1}{19} - \frac{1}{19}) \cdot 6 = (\frac{96}{19} - \frac{1}{19}) \cdot 6 = \frac{95}{19} \cdot 6 = 5 \cdot 6 = 30$$ 49. $$3\frac{7}{12} : 1 = 3\frac{7}{12}$$ 50. $$10\frac{1}{3} : 2\frac{1}{3} = \frac{31}{3} : \frac{7}{3} = \frac{31}{3} \cdot \frac{3}{7} = \frac{31 \cdot 1}{1 \cdot 7} = \frac{31}{7} = 4\frac{3}{7}$$ 51. $$2\frac{2}{3} : 1\frac{1}{31} = \frac{8}{3} : \frac{32}{31} = \frac{8}{3} \cdot \frac{31}{32} = \frac{1 \cdot 31}{3 \cdot 4} = \frac{31}{12} = 2\frac{7}{12}$$ 52. $$\frac{2}{3} \cdot \frac{6}{7} : \frac{4}{7} = \frac{2}{3} \cdot \frac{6}{7} \cdot \frac{7}{4} = \frac{1 \cdot 3 \cdot 1}{1 \cdot 1 \cdot 2} = \frac{3}{2} = 1\frac{1}{2}$$ 53. $$\frac{11}{12} : \frac{7}{12} \cdot \frac{21}{55} = \frac{11}{12} \cdot \frac{12}{7} \cdot \frac{21}{55} = \frac{1 \cdot 1 \cdot 3}{1 \cdot 1 \cdot 5} = \frac{3}{5}$$ 54. $$\frac{3}{8} : \frac{1}{9} \cdot \frac{5}{16} = \frac{3}{8} \cdot \frac{9}{1} \cdot \frac{5}{16} = \frac{3 \cdot 9 \cdot 5}{8 \cdot 1 \cdot 16} = \frac{135}{128} = 1\frac{7}{128}$$ 55. $$\frac{15}{16} : \frac{3}{8} \cdot \frac{2}{5} = \frac{15}{16} \cdot \frac{8}{3} \cdot \frac{2}{5} = \frac{3 \cdot 1 \cdot 1}{2 \cdot 1 \cdot 1} = \frac{3}{2} = 1\frac{1}{2}$$ 56. $$\frac{13}{14} : \frac{7}{26} \cdot \frac{3}{8} = \frac{13}{14} \cdot \frac{26}{7} \cdot \frac{3}{8} = \frac{13 \cdot 13 \cdot 3}{7 \cdot 7 \cdot 4} = \frac{507}{196} = 2\frac{15}{196}$$ 57. $$(3\frac{1}{6} - 2\frac{7}{15}) : 1\frac{2}{5} = (\frac{19}{6} - \frac{37}{15}) : \frac{7}{5} = (\frac{95}{30} - \frac{74}{30}) : \frac{7}{5} = \frac{21}{30} : \frac{7}{5} = \frac{7}{10} \cdot \frac{5}{7} = \frac{1 \cdot 1}{2 \cdot 1} = \frac{1}{2}$$ 58. $$(2\frac{2}{3} + 1\frac{5}{6}) : 1\frac{1}{2} = (\frac{8}{3} + \frac{11}{6}) : \frac{3}{2} = (\frac{16}{6} + \frac{11}{6}) : \frac{3}{2} = \frac{27}{6} : \frac{3}{2} = \frac{9}{2} \cdot \frac{2}{3} = \frac{3 \cdot 1}{1 \cdot 1} = 3$$ 59. $$-2\frac{1}{2} - 1\frac{2}{3} = -\frac{5}{2} - \frac{5}{3} = -\frac{15}{6} - \frac{10}{6} = -\frac{25}{6} = -4\frac{1}{6}$$ 60. $$-7\frac{5}{12} - (-1\frac{5}{6}) = -\frac{89}{12} + \frac{11}{6} = - \frac{89}{12} + \frac{22}{12} = -\frac{67}{12} = -5\frac{7}{12}$$ 61. $$3\frac{1}{4} - (-5) = \frac{13}{4} + 5 = \frac{13}{4} + \frac{20}{4} = \frac{33}{4} = 8\frac{1}{4}$$ 62. $$\frac{7}{15} - \frac{12}{17}{30} = \frac{14}{30} - \frac{12}{17}{30} = \frac{2}{30} = \frac{1}{15}$$ 63. $$\frac{3}{8} \cdot (-\frac{1}{9}) = -\frac{3 \cdot 1}{8 \cdot 9} = -\frac{1 \cdot 1}{8 \cdot 3} = -\frac{1}{24}$$ 64. $$\frac{2}{7} : (-\frac{8}{21}) = \frac{2}{7} \cdot (-\frac{21}{8}) = -\frac{2 \cdot 3}{1 \cdot 8} = -\frac{1 \cdot 3}{1 \cdot 4} = -\frac{3}{4}$$ Надеюсь, это поможет тебе в учёбе!