Ответ:

  1. \(\dfrac{5^3\cdot5^5}{5^6}=5^{3+5-6}=5^2=25\).
  2. \(\dfrac{5^9}{5^3\cdot5^4}=5^{9-3-4}=5^2=25\).
  3. \(\dfrac{5^5\cdot125}{5^9}=\dfrac{5^5\cdot5^3}{5^9}=5^{-1}=\dfrac{1}{5}\).
  4. \(\dfrac{625}{25\cdot5^2}=\dfrac{5^4}{5^2\cdot5^2}=1\).

Ответ: \(25;\ 25;\ \dfrac{1}{5};\ 1\).