Ответ:

  1. \(2\sqrt{8a}=2\sqrt{2^3a}=2^{5/2}a^{1/2}\).
  2. \(\sqrt[3]{a^2}\cdot\sqrt{a^3}=a^{2/3+3/2}=a^{13/6}\).
  3. \(\sqrt[7]{a^3}\cdot\sqrt[4]{a}=a^{3/7+1/4}=a^{19/28}\).
  4. \(3\sqrt[5]{3^4c^2}=3^{1+4/5}c^{2/5}=3^{9/5}c^{2/5}\).
  5. \(\frac18\sqrt[7]{2^5ax^3}=2^{-3+5/7}a^{1/7}x^{3/7}=2^{-16/7}a^{1/7}x^{3/7}\).
  6. \(\sqrt[3]{a^2\cdot\sqrt[4]{a}}=a^{(2+1/4)/3}=a^{3/4}\).
  7. \(\sqrt[3]{a^3\cdot\sqrt[7]{a^4}}=a^{(3+4/7)/3}=a^{25/21}\).
  8. \(\frac19\sqrt[11]{\frac{3^5}{b^5c}}=3^{-2+5/11}b^{-5/11}c^{-1/11}=3^{-17/11}b^{-5/11}c^{-1/11}\).