\[\frac{x^{2} - 11}{7} = \frac{x - x^{2}}{2}\ \ \ \ \ | \cdot 14\]
\[2 \cdot \left( x^{2} - 11 \right) = 7 \cdot \left( x - x^{2} \right)\]
\[2x^{2} - 22 = 7x - 7x^{2}\]
\[2x^{2} - 22 - 7x + 7x^{2} = 0\]
\[9x² - 7x - 22 = 0\]
\[D = b^{2} - 4ac =\]
\[= 49 - 4 \cdot 9 \cdot ( - 22) =\]
\[= 49 + 792 = 841\]
\[x_{1} = \frac{7 + 29}{18} = \frac{36}{18} = 2\]
\[x_{2} = \frac{7 - 29}{18} = - \frac{22}{18} = - \frac{11}{9} =\]
\[= - 1\frac{2}{9}\]
\[Ответ:x_{1} = 2;\ \ x_{2} = - 1\frac{2}{9}.\]