\[\boxed{\text{872.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[5 < x < 8\]
\[\textbf{а)}\ 5 \cdot 6 < 6x < 8 \cdot 6\]
\[30 < 6x < 48\]
\[\textbf{б)}\ 5 \cdot ( - 10) < - 10x <\]
\[< 8 \cdot ( - 10)\]
\[- 80 < - 10x < - 50\]
\[\textbf{в)}\ 5 - 5 < x - 5 < 8 - 5\]
\[0 < x - 5 < 3\]
\[\textbf{г)}\ 3 \cdot 5 + 2 < 3x + 2 < 3 \cdot 8 + 2\]
\[15 + 2 < 3x + 2 < 24 + 2\]
\[17 < 3x + 2 < 26\]