Ответ:

Ереже: \(a^{-n}=\frac{1}{a^n}\).

  1. \(25^{-1}=\frac{1}{25}\).
  2. \(0.125=\frac{1}{8}\), сондықтан \(0.125^{-2}=\left(\frac{1}{8}\right)^{-2}=8^2=64\).
  3. \(-2.5=-\frac{5}{2}\), сондықтан \((-2.5)^{-2}=\left(-\frac{5}{2}\right)^{-2}=\left(-\frac{2}{5}\right)^2=\frac{4}{25}\).
  4. \(\left(\frac{2}{5}\right)^{-1}=\frac{5}{2}\).
  5. \(2\frac{1}{3}=\frac{7}{3}\), сондықтан \(\left(2\frac{1}{3}\right)^{-3}=\left(\frac{7}{3}\right)^{-3}=\left(\frac{3}{7}\right)^3=\frac{27}{343}\).
  6. \(\left(-\frac{2}{7}\right)^{-2}=\left(-\frac{7}{2}\right)^2=\frac{49}{4}\).

Жауабы: 1) \(\frac{1}{25}\); 2) \(64\); 3) \(\frac{4}{25}\); 4) \(\frac{5}{2}\); 5) \(\frac{27}{343}\); 6) \(\frac{49}{4}\).