tìm x,|x| biết x=-3 1/5 |1/5 – x|=4 1/2 |2x + 1|-5=2

`x=-3 1/5`

`=> x=-16/5`

`|1/5 – x|=4 1/2`

`=> |1/5-x|=9/2`

`=>` \(\left[ \begin{array}{l}1/5-x=9/2\\1/5-x=-9/2\end{array} \right.\) 

`=> x=` \(\left[ \begin{array}{l}x=-4.3\\x=4,7\end{array} \right.\) 

`|2x + 1|-5=2`

`=> |2x+1|=2+5=7`

`=>` \(\left[ \begin{array}{l}2x+1=7\\2x+1=-7\end{array} \right.\) 

`=>` \(\left[ \begin{array}{l}x=3\\x=-4\end{array} \right.\)