Ответ:

  1. а) \(\frac{4a^2}{6ac^2}=\frac{2a}{3c^2}\).
  2. б) \(\frac{7x^2}{21xy^2}=\frac{x}{3y^2}\).
  3. в) \(\frac{56m^2n^5}{35mn^7}=\frac{8m}{5n^2}\).
  4. г) \(\frac{25p^4q}{100p^5q}=\frac{1}{4p}\).