Ответ:

  1. \(\frac{4z^5}{3m^2n}\cdot\frac{9mn^3}{2z^2}=\frac{6z^3n^2}{m}\).
  2. \(\frac{18d^2e}{5f^2}\cdot\frac{1}{6de^2}=\frac{3d}{5f^2e}\).
  3. \(\frac{16g^2h}{25i}\cdot\frac{15i^2}{8gh^2}=\frac{6gi}{5h}\).
  4. \(42k^3l^2\cdot\frac{6m^2}{7k^5l}=\frac{36m^2l}{k^2}\).
  5. Слева направо: \(\frac{9a^4}{10b}\cdot\frac{5b^3}{3a^2}\cdot\frac{a}{2b^2}=\frac{3a^3}{4}\).
  6. Слева направо: \(\frac{32c^3}{21d^2}\cdot\frac{7d^4}{8c}\cdot\frac{3c^2}{4d^2}=c^4\).