Вопрос:

Вычислите: a) 6\(\frac{1}{3}\) - 8; б) -2\(\frac{2}{7}\) + 4\(\frac{3}{5}\); в) 5\(\frac{1}{3}\) - 6\(\frac{1}{4}\); г) \(\frac{3}{8}\) : \(\left\)\(-\frac{9}{16}\right\); д) \(\frac{5}{12}\) \(\cdot\) (-6); е) -3\(\frac{2}{9}\) \(\cdot\) 3; ж) \(\frac{4}{7}\) \(\cdot\) (-49); з) -16 : \(\left\)\(-\frac{4}{9}\right\); и) -3\(\frac{1}{2}\) \(\cdot\) \(\left\)\(-1\frac{3}{7}\right\).

Ответ:

Решение:

  1. a) \(6\frac{1}{3} - 8 = \frac{19}{3} - \frac{24}{3} = -\frac{5}{3} = -1\frac{2}{3}\)
  2. б) \(-2\frac{2}{7} + 4\frac{3}{5} = -\frac{16}{7} + \frac{23}{5} = -\frac{80}{35} + \frac{161}{35} = \frac{81}{35} = 2\frac{11}{35}\)
  3. в) \(5\frac{1}{3} - 6\frac{1}{4} = \frac{16}{3} - \frac{25}{4} = \frac{64}{12} - \frac{75}{12} = -\frac{11}{12}\)
  4. г) \(\frac{3}{8} : \left(-\frac{9}{16}\right) = \frac{3}{8} \cdot \left(-\frac{16}{9}\right) = -\frac{3 \cdot 16}{8 \cdot 9} = -\frac{1 \cdot 2}{1 \cdot 3} = -\frac{2}{3}\)
  5. д) \(\frac{5}{12} \cdot (-6) = -\frac{5 \cdot 6}{12} = -\frac{5}{2} = -2.5\)
  6. е) \(-3\frac{2}{9} \cdot 3 = -\frac{29}{9} \cdot 3 = -\frac{29 \cdot 3}{9} = -\frac{29}{3} = -9\frac{2}{3}\)
  7. ж) \(\frac{4}{7} \cdot (-49) = -\frac{4 \cdot 49}{7} = -4 \cdot 7 = -28\)
  8. з) \(-16 : \left(-\frac{4}{9}\right) = -16 \cdot \left(-\frac{9}{4}\right) = \frac{16 \cdot 9}{4} = 4 \cdot 9 = 36\)
  9. и) \(-3\frac{1}{2} \cdot \left(-1\frac{3}{7}\right) = \left(-\frac{7}{2}\right) \cdot \left(-\frac{10}{7}\right) = \frac{7 \cdot 10}{2 \cdot 7} = 5\)

Ответ: а) \(-1\frac{2}{3}\); б) \(2\frac{11}{35}\); в) \(-\frac{11}{12}\); г) \(-\frac{2}{3}\); д) \(-2.5\); е) \(-9\frac{2}{3}\); ж) \(-28\); з) \(36\); и) \(5\).