Ответ:

  1. \(3^4=3\cdot3\cdot3\cdot3=81\).
  2. \(5^2=5\cdot5=25\).
  3. \(2^8=256\).
  4. \((-\frac{2}{3})^3=-\frac{2^3}{3^3}=-\frac{8}{27}\).
  5. \(0{,}8^3=0{,}8\cdot0{,}8\cdot0{,}8=0{,}512\).
  6. \((\frac{2}{5})^4=\frac{2^4}{5^4}=\frac{16}{625}\).