\(A=\left|x+2017\right|+\left|x+2019\right|\\ \Leftrightarrow A=\left|x+2017\right|+\left|2019-x\right|\\ \Leftrightarrow A_{min}=4036\)
+Dấu ''='' xảy ra khi
\(\left\{{}\begin{matrix}x+2017\ge0\\x+2019\ge0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ge2017\\x\le2019\end{matrix}\right.\)
\(\Leftrightarrow2017\le x\le2019\)
+Vậy \(A_{min}=4036\) khi \(2017\le x\le2019\)
Ta có
/x+2017/+/x+2019/=/x+2017/+/2019-x/≥/x+2017+2019-x/
=/4036/=4036
GTNN của A bang 4036
khi đó x≥2019 hoặc x≤2017
