\[\boxed{\mathbf{975\ (975).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[x^{2} + ax + a - 2 = 0\]
\[\left\{ \begin{matrix} x_{1} + x_{2} = - a \\ x_{1}x_{2} = a - 2 \\ \end{matrix} \right.\ \]
\[x_{1}^{2} + x_{2}^{2} = \left( x_{1} + x_{2} \right)^{2} - 2x_{1}x_{2} =\]
\[= ( - a)^{2} - 2 \cdot (a - 2) =\]
\[= a^{2} - 2a + 4\]
\[y = a^{2} - 2a + 4\ \]
\[- \frac{b}{2a} = \frac{2}{2a} = \frac{1}{1} = 1\]
\[Ответ:при\ a = 1.\]