Giải:
Đặt: \(A=-\left|x-100\right|-\left|y+200\right|-1\)
Ta có:
\(\left\{{}\begin{matrix}\left|x-100\right|\ge0\\\left|y+200\right|\ge0\end{matrix}\right.\)
\(\Leftrightarrow-\left|x-100\right|-\left|y+200\right|\le0\)
\(\Leftrightarrow-\left|x-100\right|-\left|y+200\right|-1\le-1\)
\(\Leftrightarrow A\le-1\)
\(\Leftrightarrow A_{Max}=-1\)
\("="\Leftrightarrow\left\{{}\begin{matrix}x-100=0\\y+200=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=100\\y=-200\end{matrix}\right.\)
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