a) |3x-2|=7
=> 3x-2=7 hoặc 3x-2=-7
=> 3x=9 hoặc 3x=-5
=> x=3 hoặc x=\(-\dfrac{5}{3}\)
\(\left|\dfrac{1}{4}-\dfrac{2x}{3}\right|=\dfrac{7}{6}\\ =>\left[{}\begin{matrix}\dfrac{1}{4}-\dfrac{2}{3}x=\dfrac{7}{6}\\\dfrac{1}{4}-\dfrac{2}{3}x=-\dfrac{7}{6}\end{matrix}\right.\\ =>\left[{}\begin{matrix}\dfrac{2}{3}x=\dfrac{1}{4}-\dfrac{7}{6}=-\dfrac{11}{12}\\\dfrac{2}{3}x=\dfrac{1}{4}-\left(-\dfrac{7}{6}\right)=\dfrac{17}{12}\end{matrix}\right.\)
\(=>\left[{}\begin{matrix}x=-\dfrac{11}{12}:\dfrac{2}{3}=-\dfrac{11}{8}\\x=\dfrac{17}{12}:\dfrac{2}{3}=\dfrac{17}{8}\end{matrix}\right.\)
c) |8-|x+3||=2
=> 8-|x+3|=2 hoặc 8-|x+3|=-2
=> |x+3|=6 hoặc |x+3|=10
=> x+3=6 hoặc x+3=-6 hoặc x+3=10 hoặc x+3=-10
=> x=3 hoặc x=-9 hoặc x=7 hoặc x=-13