Áp dụng \(\left|A\right|+\left|B\right|\ge\left|A+B\right|\) khi \(AB\ge0\)
Ta có: \(\left|x-2016\right|+\left|x-2017\right|=\left|x-2016\right|+\left|2017-x\right|\ge\left|x-2016+2017-x\right|=1\)
Dấu "=" khi \(\left(x-2016\right)\left(2017-x\right)\ge0\Leftrightarrow2016\le x\le2017\)
Vậy khi \(2016\le x\le2017\) thì \(\left|x-2016\right|+\left|x-2017\right|=1\)