\[\ |3 - 7x| = 19\]
\[3 - 7x = 19\]
\[- 7x = 16\]
\[x = - \frac{16}{7}\]
\[x = - 2\frac{2}{7}\]
\[3 - 7x = - 19\]
\[- 7x = - 22\]
\[x = \frac{22}{7}\]
\[x = 3\frac{1}{7}\]
\[Ответ:\ x = - 2\frac{2}{7}\ \ и\ \ \ x = 3\frac{1}{7}.\]
\[\ |10x + 1| > 21\]
\[\left\lbrack \begin{matrix} 10x + 1 > 21\ \ \ \\ 10x + 1 < - 21 \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\left\lbrack \begin{matrix} 10x > 20\ \ \ \\ 10x < - 22 \\ \end{matrix} \right.\ \text{\ \ \ \ }\]
\[\left\lbrack \begin{matrix} x > 2\ \ \ \ \ \ \ \\ x < - 2,2 \\ \end{matrix} \right.\ \]
\[Ответ:\ x \in ( - \infty; - 2,2) \cup (2; + \infty).\]