Решите неравенство: 3<=(5x+2)/4<=4.

\[3 \leq \frac{5x + 2}{4} \leq 4\]

\[12 \leq 5x + 2 \leq 16\]

\[10 \leq 5x \leq 14\]

\[2 \leq x \leq 2,8\]

\[Ответ:\ \lbrack 2;2,8\rbrack.\]