\[\boxed{\text{573}\text{\ (573)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ x² + x - 42 \leq 0\]
\[x^{2} + x - 42 = 0\]
\[x_{1} + x_{2} = - 1;\ \ \ \ \ x_{1} \cdot x_{2} = - 42\]
\[x_{1} = - 7;\ \ x_{2} = 6.\]
\[(x + 7)(x - 6) \leq 0\]
\[- 7 \leq x \leq 6.\]
\[\textbf{б)}\ (x + 11)(x + 4)(x - 1) > 0\]
\[x = - 11;\ \ x = - 4;\ \ x = 1\]
\[x \in ( - 11;\ - 4) \cup (1;\ + \infty).\]