\(7.\left|-2x-1\right|=\dfrac{1}{6}\)
\(\Rightarrow-2x-1=\pm\dfrac{1}{6}\)
\(TH1:-2x-1=\dfrac{1}{6}\)
\(-2x=\dfrac{1}{6}+1\)
\(-2x=\dfrac{7}{6}\)
\(x=\dfrac{7}{6}:\left(-2\right)\)
\(x=\dfrac{-7}{12}\)
\(TH2:-2x-1=\dfrac{-1}{6}\)
\(-2x=\dfrac{-1}{6}+1\)
\(-2x=\dfrac{5}{6}\)
\(x=\dfrac{5}{6}:\left(-2\right)\)
\(x=\dfrac{-5}{12}\)