• 841. Вычислите: 3 19 4 11 33 a) (-) - 1:1,5. -- 5 25 16 8 7 3-8 6)()+-2-3+-2. 12 4 27 5 28 42 28 1 31-1- B) -(+)--1: 45 3 15 5 5 8 17 3 54 11 13 r)-1-+-+:-+-1- 19 8 4 8 14 7 14 14

Ответ: a) -1\frac{3}{8}; б) 2\frac{19}{24}; в) -1\frac{11}{21}; г) 1\frac{23}{133}.

• a)\[\left(\frac{3}{5} - \frac{19}{25}\right) \cdot 4\frac{11}{16} - (1 : 1,5) \cdot \left(-3\frac{3}{8}\right) = \]\[ = \left(\frac{15}{25} - \frac{19}{25}\right) \cdot \frac{75}{16} - \frac{2}{3} \cdot \left(-\frac{27}{8}\right) = \]\[ = -\frac{4}{25} \cdot \frac{75}{16} + \frac{2}{3} \cdot \frac{27}{8} = \]\[ = -\frac{1}{1} \cdot \frac{3}{4} + \frac{1}{1} \cdot \frac{9}{4} = \]\[ = -\frac{3}{4} + \frac{9}{4} = \frac{6}{4} = \frac{3}{2} = 1\frac{1}{2}\]
• б)\[\left(\frac{7}{12} + \frac{3}{4}\right) : \left(-\frac{8}{27}\right) + \left(2 - 3\frac{2}{5}\right) \cdot \frac{25}{28} = \]\[ = \left(\frac{7}{12} + \frac{9}{12}\right) : \left(-\frac{8}{27}\right) + \left(\frac{10}{5} - \frac{17}{5}\right) \cdot \frac{25}{28} = \]\[ = \frac{16}{12} : \left(-\frac{8}{27}\right) + \left(-\frac{7}{5}\right) \cdot \frac{25}{28} = \]\[ = \frac{4}{3} \cdot \left(-\frac{27}{8}\right) + \left(-\frac{1}{1}\right) \cdot \frac{5}{4} = \]\[ = -\frac{9}{2} - \frac{5}{4} = -\frac{18}{4} - \frac{5}{4} = -\frac{23}{4} = -5\frac{3}{4}\]
• в)\[\frac{42}{45} : \left(\frac{2}{3} + \frac{8}{15}\right) - 1 : \left(3 - 1\frac{1}{5}\right) = \]\[ = \frac{42}{45} : \left(\frac{10}{15} + \frac{8}{15}\right) - 1 : \left(\frac{15}{5} - \frac{6}{5}\right) = \]\[ = \frac{42}{45} : \frac{18}{15} - 1 : \frac{9}{5} = \]\[ = \frac{42}{45} \cdot \frac{15}{18} - \frac{5}{9} = \]\[ = \frac{7}{3} \cdot \frac{1}{3} - \frac{5}{9} = \frac{7}{9} - \frac{5}{9} = \frac{2}{9}\]
• г)\[\frac{8}{19} \cdot \left(1\frac{7}{8} - \frac{3}{4} + 3\frac{5}{8}\right) + \frac{5}{14} : \left(\frac{4}{7} + \frac{11}{14} - 1\frac{3}{14}\right) = \]\[ = \frac{8}{19} \cdot \left(\frac{15}{8} - \frac{6}{8} + \frac{29}{8}\right) + \frac{5}{14} : \left(\frac{8}{14} + \frac{11}{14} - \frac{17}{14}\right) = \]\[ = \frac{8}{19} \cdot \frac{38}{8} + \frac{5}{14} : \frac{2}{14} = \]\[ = \frac{8}{19} \cdot \frac{38}{8} + \frac{5}{14} \cdot \frac{14}{2} = \]\[ = 2 + \frac{5}{2} = \frac{4}{2} + \frac{5}{2} = \frac{9}{2} = 4\frac{1}{2}\]

Ответ: a) -1\frac{3}{8}; б) 2\frac{19}{24}; в) -1\frac{11}{21}; г) 1\frac{23}{133}.