Ответ:

  1. а) \(1\frac{4}{11}\cdot2\frac{1}{7}\cdot3\frac{4}{7}=\frac{15}{11}\cdot\frac{15}{7}\cdot\frac{25}{7}=\frac{5625}{539}\).
  2. б) \(28\frac{3}{4}-(3\frac{1}{5}+2\frac{1}{4})\cdot\frac{5}{100}=\frac{11500}{400}-\frac{109}{400}=\frac{11391}{400}=28\frac{191}{400}\).

Ответ: а) \(\frac{5625}{539}\); б) \(28\frac{191}{400}\).