a) \(\Rightarrow\left|\dfrac{5}{6}-\dfrac{2}{3}x\right|=\dfrac{7}{6}\)
\(\Rightarrow\left[{}\begin{matrix}\dfrac{5}{6}-\dfrac{2}{3}x=\dfrac{7}{6}\\\dfrac{5}{6}-\dfrac{2}{3}x=-\dfrac{7}{6}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=3\end{matrix}\right.\)
b) \(\Rightarrow\dfrac{11}{4}-\dfrac{7}{13}x=-\dfrac{1}{2}\)
\(\Rightarrow\dfrac{7}{13}x=\dfrac{13}{4}\Rightarrow x=\dfrac{169}{28}\)
\(\Rightarrow\left|\dfrac{5}{6}-\dfrac{2}{3}x\right|=\dfrac{11}{12}-\dfrac{1}{4}=\dfrac{2}{3}\\ \Rightarrow\left[{}\begin{matrix}\dfrac{5}{6}-\dfrac{2}{3}x=\dfrac{2}{3}\\\dfrac{2}{3}x-\dfrac{5}{6}=\dfrac{2}{3}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}\dfrac{2}{3}x=\dfrac{1}{6}\\\dfrac{2}{3}x=\dfrac{3}{2}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{4}\\x=\dfrac{9}{4}\end{matrix}\right.\)
bài a mik biết làm rồi có ai chỉ mình bài b không 
