Tìm x biết:
| 3 - x | = x - 5
Giải:
Ta có: \(3-x=x-5\) hoặc \(3-x=-\left(x-5\right)\)
\(TH1:3-x=x-5\)
\(2x=3+5\)
\(2x=8\)
\(\Rightarrow x=4\)
\(TH2:3-x=-\left(x-5\right)\)
\(3-x=-x+5\)
\(-x-x=5-3\)
\(2.\left(-x\right)=2\)
\(-x=1\)
\(\Rightarrow x=-1\)