Ответ:

  1. \(\dfrac{5}{x^3}=5x^{-3}\).
  2. \(\dfrac{2m^3}{n^5}=2m^3n^{-5}\).
  3. \(\dfrac{1}{a^3b^2}=a^{-3}b^{-2}\).
  4. \(\dfrac{2x}{a-b}=2x(a-b)^{-1}\).
  5. \(\dfrac{a}{b}=ab^{-1}\).
  6. \(\dfrac{p^5}{q^4}=p^5q^{-4}\).
  7. \(\dfrac{c}{a^3b^4}=ca^{-3}b^{-4}\).
  8. \(\dfrac{(x-y)^2}{25(x+y)^4}=\dfrac{1}{25}(x-y)^2(x+y)^{-4}\).

Использовано правило \(\dfrac{1}{u^k}=u^{-k}\).