\[\boxed{\text{1241.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\text{A\ }\left( a;\frac{1}{247} \right)\ \ и\ \ \ \]
\[B\ (843;b)\text{\ \ } \in y = x^{- 1}\]
\[y = x^{- 1};\ \ y = \frac{1}{x}\]
\[\left\{ \begin{matrix} \frac{1}{247} = \frac{1}{a} \\ b = \frac{1}{843} \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\left\{ \begin{matrix} a = 247 \\ b = \frac{1}{843} \\ \end{matrix} \right.\ \]
\[Ответ:a = 247;\ \ b = \frac{1}{843}.\]