\[y = ax^{2} + (a + 2)x + 2\ \ \]
\[при\ a = 0:\]
\[\ 2x + 2 = 0\ \ \]
\[x = - 1.\]
\[ax² + (a + 2)x + 2 = 0\]
\[D = a^{2} + 4a + 4 - 8a =\]
\[= a^{2} - 4a + 4 = (a - 2)^{2}\]
\[(a - 2)^{2} = 0\]
\[a = 2.\]
\[Ответ:при\ a = 2;\ a = 0.\]