a) \(\left|x+\dfrac{4}{5}\right|-\dfrac{1}{2}=\dfrac{3}{2}\)
\(\Leftrightarrow\left|x+\dfrac{4}{5}\right|=\dfrac{3}{2}+\dfrac{1}{2}\)
\(\Leftrightarrow\left|x+\dfrac{4}{5}\right|=2\)
* \(x+\dfrac{4}{5}=2\)
\(\Leftrightarrow x=2-\dfrac{4}{5}\)
\(\Leftrightarrow x=\dfrac{6}{5}\)
* \(x+\dfrac{4}{5}=-2\)
\(\Leftrightarrow x=-2-\dfrac{4}{5}\)
\(\Leftrightarrow x=\dfrac{-14}{5}\)
Vậy ......................
b) \(\left|x-1\right|+2x=4\)
\(\Leftrightarrow\left|x-1\right|=4-2x\)
* \(x-1=4-2x\)
\(\Leftrightarrow x+2x=4+1\)
\(\Leftrightarrow3x=5\)
\(\Leftrightarrow x=\dfrac{5}{3}\)
* \(x-1=-\left(4-2x\right)\)
\(\Leftrightarrow x-1=-4+2x\)
\(\Leftrightarrow x-2x=-4+1\)
\(\Leftrightarrow-x=-3\)
\(\Leftrightarrow x=3\)
Vậy .................................
