Ответ:

  1. а) \(6\frac{1}{3}-8=\frac{19}{3}-\frac{24}{3}=-\frac{5}{3}=-1\frac{2}{3}\).
  2. б) \(\left(-\frac{9}{16}\right):\frac{3}{8}=-\frac{9}{16}\cdot\frac{8}{3}=-\frac{3}{2}=-1\frac{1}{2}\).
  3. в) \(4\frac{1}{5}-2\frac{3}{7}=\frac{21}{5}-\frac{17}{7}=\frac{147-85}{35}=\frac{62}{35}=1\frac{27}{35}\).
  4. г) \(2\frac{2}{7}+4\frac{3}{5}=\frac{16}{7}+\frac{23}{5}=\frac{80+161}{35}=\frac{241}{35}=6\frac{31}{35}\).
  5. д) \((-6)\cdot\left(-\frac{5}{12}\right)=\frac{30}{12}=\frac{5}{2}=2\frac{1}{2}\).
  6. е) \(-3\frac{2}{9}\cdot3=-\frac{29}{9}\cdot3=-\frac{29}{3}=-9\frac{2}{3}\).
  7. ж) \(-1\frac{1}{2}\cdot\left(-1\frac{3}{7}\right)=-\frac{3}{2}\cdot\left(-\frac{10}{7}\right)=\frac{15}{7}=2\frac{1}{7}\).

Ответ: а) \(-1\frac{2}{3}\); б) \(-1\frac{1}{2}\); в) \(1\frac{27}{35}\); г) \(6\frac{31}{35}\); д) \(2\frac{1}{2}\); е) \(-9\frac{2}{3}\); ж) \(2\frac{1}{7}\).