\[\boxed{\text{327\ (327).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ (x - 2)(x - 5)(x - 12) > 0\]
\[x \in (2;5) \cup (12; + \infty).\]
\[\textbf{б)}\ (x + 7)(x + 1)(x - 4) < 0\]
\[x \in ( - \infty;\ - 7) \cup ( - 1;4).\]
\[\textbf{в)}\ x(x + 1)(x + 5)(x - 8) > 0\]
\[(x + 5)(x + 1)x(x - 8) > 0\]
\[x \in ( - \infty;\ - 5) \cup ( - 1;0) \cup\]
\[\cup (8;\ + \infty).\]