+, \(5x^2+5y^2+8xy-2x+2y+2=0\)
\(\Leftrightarrow4x^2+x^2+4y^2+y^2+8xy-2x+2y+1+1=0\)
\(\Leftrightarrow\left(4x^2+8xy+4y^2\right)+\left(x^2-2x+1\right)+\left(y^2+2y+1\right)=0\)
\(\Leftrightarrow\left(2x+2y\right)^2+\left(x-1\right)^2+\left(y+1\right)^2=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+2y=0\\x-1=0\\y+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-y\\x=1\\y=-1\end{matrix}\right.\left(TM\right)\)
+, Thay x = 1 ; y = -1 vào M ta được :
\(M_{\left(1;-1\right)}=\left(1-1\right)^{2019}+\left(1-2\right)^{2020}+\left(-1+1\right)^{2021}\)
\(=1^{2020}=1\)
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