a. \(\left|x\right|=\dfrac{2}{3}\Rightarrow x=\pm\dfrac{2}{3}\)
Vậy \(x=\pm\dfrac{2}{3}\)
b. \(4x-\left(x+\dfrac{1}{2}\right)=2x-\left(\dfrac{1}{2}-5\right)\)
\(\Rightarrow4x-x-\dfrac{1}{2}=2x-\dfrac{1}{2}+5\)
\(\Rightarrow4x-x-2x=-\dfrac{1}{2}+5+\dfrac{1}{2}\)
\(\Rightarrow x=5\)
Vậy x = 5