\[\boxed{\text{1172.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ 10^{- 6} = \frac{1}{10^{6}}\]
\[\textbf{б)}\ 9^{- 2} = \frac{1}{9^{2}}\]
\[\textbf{в)}\ a^{- 1} = \frac{1}{a}\]
\[\textbf{г)}\ x^{- 20} = \frac{1}{x^{20}}\]
\[\textbf{д)}\ \left( \text{ab} \right)^{- 3} = \frac{1}{\left( \text{ab} \right)^{3}}\]
\[\textbf{е)}\ (a + b)^{- 4} = \frac{1}{(a + b)^{4}}\]