\[\boxed{\text{286}\text{\ (286)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 13 \cdot (5x - 1) -\]
\[- 15 \cdot (4x + 2) < 0\]
\[65x - 13 - 60x - 30 < 0\]
\[5x - 43 < 0\ \]
\[x < 8,6.\]
\[\textbf{б)}\ 6 \cdot (7 - 0,2x) -\]
\[- 5 \cdot (8 - 0,4x) > 0\]
\[42 - 1,2x - 40 + 2x > 0\]
\[0,8x + 2 > 0\]
\[0,8x > - 2\]
\[x > - 2,5.\]