\(\dfrac{4}{7}< \left|x-\dfrac{8}{7}\right|< \dfrac{5}{7}\)
=>\(\left[{}\begin{matrix}\dfrac{4}{7}< x-\dfrac{8}{7}< \dfrac{5}{7}\\-\dfrac{5}{7}< x-\dfrac{8}{7}< -\dfrac{4}{7}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{12}{7}< x< \dfrac{13}{7}\\\dfrac{3}{7}< x< \dfrac{4}{7}\end{matrix}\right.\Leftrightarrow x\in\varnothing\)