Ответ:

  1. \(64^{1/2}=8\);
  2. \(27^{1/3}=3\);
  3. \(8^{2/3}=4\);
  4. \(81^{3/4}=27\);
  5. \(16^{-0.75}=16^{-3/4}=\frac18\);
  6. \(9^{-1.5}=9^{-3/2}=\frac1{27}\).

Ответ: 8; 3; 4; 27; \(\frac18\); \(\frac1{27}\).