1. Вычислите: a) 1,25 - 3,8; б) -0,4 - \frac{1}{8}; в) -\frac{2}{9} - (-\frac{5}{6}); г) 1\frac{5}{7} - (-3\frac{11}{14}) + (-2\frac{1}{4}). a) 2,3 - 4,42; б) -\frac{3}{4} - 0,2; в) -2\frac{7}{8} - (-\frac{1}{6}); г) 8\frac{2}{3} - (-4\frac{3}{8}) + (-6\frac{1}{36}).

a) 1,25 - 3,8 = -2,55 б) -0,4 - \frac{1}{8} = -\frac{4}{10} - \frac{1}{8} = -\frac{16}{40} - \frac{5}{40} = -\frac{21}{40} = -0,525 в) -\frac{2}{9} - (-\frac{5}{6}) = -\frac{2}{9} + \frac{5}{6} = -\frac{4}{18} + \frac{15}{18} = \frac{11}{18} г) 1\frac{5}{7} - (-3\frac{11}{14}) + (-2\frac{1}{4}) = \frac{12}{7} + \frac{53}{14} - \frac{9}{4} = \frac{24}{14} + \frac{53}{14} - \frac{9}{4} = \frac{77}{14} - \frac{9}{4} = \frac{154}{28} - \frac{63}{28} = \frac{91}{28} = \frac{13}{4} = 3,25 a) 2,3 - 4,42 = -2,12 б) -\frac{3}{4} - 0,2 = -0,75 - 0,2 = -0,95 в) -2\frac{7}{8} - (-\frac{1}{6}) = -\frac{23}{8} + \frac{1}{6} = -\frac{69}{24} + \frac{4}{24} = -\frac{65}{24} = -2\frac{17}{24} г) 8\frac{2}{3} - (-4\frac{3}{8}) + (-6\frac{1}{36}) = \frac{26}{3} + \frac{35}{8} - \frac{217}{36} = \frac{26*24}{3*24} + \frac{35*9}{8*9} - \frac{217*2}{36*2} = \frac{624}{72} + \frac{315}{72} - \frac{434}{72} = \frac{939-434}{72} = \frac{505}{72} = 7\frac{1}{72}