Với mọi x, y ta có :
\(\left\{{}\begin{matrix}\left(x-5\right)^{10}\ge0\\\left|y^2-9\right|\ge0\end{matrix}\right.\)
\(\Leftrightarrow\left(x-5\right)^{10}+\left|y^2-9\right|\ge0\)
Mà \(\left(x-5\right)^{10}+\left|y^2-9\right|=0\)
Dấu "=" xảy ra khi :
\(\Leftrightarrow\left\{{}\begin{matrix}\left(x-5\right)^{10}=0\\\left|y^2-9\right|=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x-5=0\\y^2-9=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=5\\\left[{}\begin{matrix}y=3\\y=-3\end{matrix}\right.\end{matrix}\right.\)
Vậy..