\[\boxed{\text{1174.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ 8 = 2³\]
\[4 = 2^{2}\]
\[2 = 2^{1}\]
\[1 = 2^{0}\]
\[\frac{1}{2} = 2^{- 1}\]
\[\frac{1}{4} = 2^{- 2}\]
\[\frac{1}{8} = 2^{- 3}\]
\[\textbf{б)}\frac{1}{125} = 5^{- 3}\]
\[\frac{1}{25} = 5^{- 2}\]
\[\frac{1}{5} = 5^{- 1}\]
\[1 = 5^{0}\]
\[5 = 5^{1}\]
\[25 = 5^{2}\]
\[125 = 5³\]