(7) Given that the real number $x$ satisfies $|2 x+1|+|2 x-5|=6$, then the range of values for $x$ is $\qquad$
(7) $\left[-\frac{1}{2}, \frac{5}{2}\right]$ Hint: Since
$$
|2 x+1|+|2 x-5| \geqslant|(2 x+1)+(5-2 x)|=6,
$$

equality holds if and only if $(2 x+1)(2 x-5) \leqslant 0$, i.e., $-\frac{1}{2} \leqslant x \leqslant \frac{5}{2}$.