\[\boxed{\text{765\ (765).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)} - 2 < \frac{4x - 1}{5} < 2\]
\[- 10 < 4x - 1 < 10\]
\[- 9 < 4x < 11\]
\[- \frac{9}{4} < x < \frac{11}{4}\]
\[- 2\frac{1}{4} < x < 2\frac{3}{4}\]
\[Ответ:\left( - 2\frac{1}{4};2\frac{3}{4} \right).\]
\[\textbf{б)}\ 0,2 \leq \frac{1 - 5x}{20} \leq 0,4\]
\[4 \leq 1 - 5x \leq 8\]
\[3 \leq - 5x \leq 7\]
\[- 7 \leq 5x \leq - 3\]
\[- \frac{7}{5} \leq x \leq - \frac{3}{5}\]
\[Ответ:\left\lbrack - 1\frac{2}{5};\ - \frac{3}{5} \right\rbrack.\]