\[= 4a^{2} - 8a + 4 - 12a^{2} + 12 =\]
\[= - 8a^{2} - 8a + 16 < 0\]
\[- 8a^{2} - 8a + 16 = 0\ \ \ \ |\ :( - 8)\]
\[a^{2} + a - 2 = 0\]
\[a_{1} + a + 2 = - 1\ \ \ \ \ \ \ a_{1} = - 2\]
\[a_{1}a_{2} = - 2\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ a_{2} = 1\]