\[x^{2} + 2x - 5 = 0\]
\[x_{1} + x_{2} = - 2;\ \ \ \ \ \ \ \ x_{1}x_{2} = - 5\]
\[\frac{1}{x_{1}} + \frac{1}{x_{2}} = \frac{x_{1} + x_{2}}{x_{1}x_{2}} = \frac{- 2}{- 5} = \frac{2}{5} =\]
\[= 0,4\]
\[\frac{1}{x_{1}} \cdot \frac{1}{x_{2}} = \frac{1}{x_{1}x_{2}} = \frac{1}{- 5} = - \frac{1}{5} =\]
\[= - 0,2\]
\[x^{2} - 0,4x - 0,2 = 0.\]