\[ax + 7a < 2 - 4x\]
\[ax + 4x < 2 - 7a\]
\[(a + 4)x < 2 - 7a\]
\[1)\ a = - 4:\]
\[0 \cdot x < 30 \Longrightarrow верно\ \]
\[при\ любом\ x \Longrightarrow ( - \infty; + \infty).\]
\[2)\ a > - 4:\]
\[x < \frac{2 - 7a}{a + 4} \Longrightarrow \left( - \infty;\frac{2 - 7a}{a + 4} \right).\]
\[3)\ a < - 4:\]
\[x > \frac{2 - 7a}{a + 4} \Longrightarrow \left( \frac{2 - 7a}{a + 4}; + \infty \right).\]
\[Ответ:\ \ любое\ x \in ( - \infty; + \infty)\ \]
\[для\ a = - 4;\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ любое\ x \in \left( - \infty;\frac{2 - 7a}{a + 4} \right)\text{\ \ }\]
\[для\ a > - 4;\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ любое\ x \in \left( \frac{2 - 7a}{a + 4}; + \infty \right)\text{\ \ }\]
\[для\ a < - 4.\]