Question

Tìm x biết

|x-2|=x

Answer 1

`|x-2|=x\   (ĐK:x\ge 0)`

`=>x-2=x\   (1)` hoặc `x-2=-x\   (2)`

`(1)=>x-x=2`

`=>0=2` (Vô lí)

`(2)=>x+x=2`

`=>2x=2`

`=>x=1` (TMDK)

Vậy `x=1`

 

Answer 2

\(\left|x-2\right|=x\\ \Rightarrow\left\{{}\begin{matrix}x-2=x\\x-2=-x\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x-x=2\\x+x=2\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}0=2\left(vô.lí\right)\\2x=2\end{matrix}\right.\\ 2x=2\\ x=1\)