\[\left( a^{2} + 2a - 8 \right)x = a² - 4\]
\[x = \frac{a^{2} - 4}{a^{2} + 2a - 8} =\]
\[a^{2} + 2a - 8 = 0\]
\[a_{1} + a_{2} = - 2;\ \ a_{1} \cdot a_{2} = - 8\]
\[a_{1} = - 4;\ \ \ \ \ \ \ \ \ \ \ \ a_{2} = 2\]
\[a^{2} + 2a - 8 = (a + 4)(a - 2).\]
\[1)\ \ a = 2:\]
\[\left( 2^{2} + 2 \cdot 2 - 8 \right)x = 2^{2} - 4\]
\[0 \cdot x = 0 \Longrightarrow x - любое.\]
\[2)\ \ a = - 4:\]
\[нет\ решения.\]
\[3)\ \ a = - 2:\]
\[x = 0.\]
\[4)\ \ a \neq 2,\ a \neq - 4,\ a \neq - 2:\]
\[x = \frac{a + 2}{a + 4}.\]