\[\frac{1}{x_{1}}\ \ \ и\ \ \ \frac{1}{x_{2}} - корни.\]
\[\frac{1}{x_{1}} + \frac{1}{x_{2}} = \frac{x_{2} + x_{1}}{x_{1} \cdot x_{2}} = \frac{- 7}{- 11} = \frac{7}{11}\]
\[\frac{1}{x_{1}} \cdot \frac{1}{x_{2}} = \frac{1}{x_{1} \cdot x_{2}} = - \frac{1}{11}\]
\[x^{2} - \frac{7}{11}x - \frac{1}{11} = 0.\]
\(11x^{2} - 7x - 1 = 0.\)