Đáp án:
c.$x\in\{\dfrac{-51}{10},\dfrac{61}{10}\}$
Giải thích các bước giải:
c.$6-\Big|\dfrac{1}{2}-x\Big|=\dfrac{2}{5}$
$\rightarrow \Big|\dfrac{1}{2}-x\Big|=6-\dfrac{2}{5}$
$\rightarrow \Big|\dfrac{1}{2}-x\Big|=\dfrac{28}{5}$
$\rightarrow \Bigg[^{\quad\dfrac{1}{2}-x=\dfrac{28}{5}}_{\quad\dfrac{1}{2}-x=\dfrac{-28}{2}}$
$\rightarrow \Bigg[^{\quad x=\dfrac{1}{2}-\dfrac{28}{5}}_{\quad x=\dfrac{1}{2}+\dfrac{28}{2}}$
$\rightarrow \Bigg[^{\quad x=\dfrac{-51}{10}}_{\quad x=\dfrac{61}{10}}$
