\[\boxed{\mathbf{4.}\mathbf{75}}\]
\[1)\ а)\ 239;\]
\[\textbf{б)}\ 1,7;\]
\[\textbf{в)}\ 0;\]
\[\textbf{г)}\frac{2}{3};\ \]
\[\textbf{д)}\ \frac{7}{6};\]
\[\textbf{е)}\ 2\frac{1}{11}.\]
\[2)\ а)\ x = 2:\]
\[\ |2x - 6| - 2x =\]
\[= |2 \cdot 2 - 6| - 2 \cdot 2 = 2 - 4 =\]
\[= - 2.\]
\[\textbf{б)}\ x = 2:\]
\[|3x - 8| - 3x =\]
\[= |3 \cdot 2 - 8| - 3 \cdot 2 = 2 - 6 =\]
\[= - 4.\]
\[\textbf{в)}\ x = - 3:\]
\[|6 + 4x| - 5x =\]
\[= \left| 6 + 4 \cdot ( - 3) \right| - 5 \cdot ( - 3) =\]
\[= 6 + 15 = 21.\]
\[\textbf{г)}\ x = - 2:\]
\[|7 + 5x| - 4x =\]
\[= \left| 7 + 5 \cdot ( - 2) \right| - 4 \cdot ( - 2) =\]
\[= 3 + 8 = 11.\]