Ответ:

  1. \(\sqrt{x}=x^{\frac12}\).
  2. \(\sqrt[7]{6^5}=6^{\frac57}\).
  3. \(\sqrt[5]{2^{-2}}=2^{-\frac25}\).
  4. \(\sqrt[8]{a^7-b^7}=(a^7-b^7)^{\frac18}\).

Ответ: 1) \(x^{\frac12}\); 2) \(6^{\frac57}\); 3) \(2^{-\frac25}\); 4) \((a^7-b^7)^{\frac18}\).