Ответ:

  1. \(10^{-1}+5^{-2}=\frac{1}{10}+\frac{1}{25}=\frac{5}{50}+\frac{2}{50}=\frac{7}{50}\).
  2. \(\left(\frac{2}{3}\right)^{-1}+(-1{,}7)^0-2^{-3}=\frac{3}{2}+1-\frac{1}{8}=\frac{12}{8}+\frac{8}{8}-\frac{1}{8}=\frac{19}{8}\).
  3. \(\left(\frac{3}{4}\right)^{-2}\cdot2^{-3}=\frac{16}{9}\cdot\frac{1}{8}=\frac{2}{9}\).