Đặt \(\left\{{}\begin{matrix}x+y=a\\xy=b\end{matrix}\right.\left(a\ge4b\right)\)
\(hpt\Leftrightarrow\left\{{}\begin{matrix}\left(2x^2+2y^2+4xy\right)+\left(x+y\right)+1+xy=0\\\left(x^2+2xy+y^2\right)+12\left(x+y\right)+10+2xy=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2\left(x+y\right)^2+\left(x+y\right)+1+xy=0\\\left(x+y\right)^2+12\left(x+y\right)+10+2xy=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2a^2+a+1+b=0\\a^2+12a+10+2b=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}4a^2+2a+2+2b=0\\a^2+12a+10+2b=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2a^2+a+1+b=0\\3a^2-10a-8=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2a^2+a+1+b=0\\\left[{}\begin{matrix}a=4\\a=-\frac{2}{3}\end{matrix}\right.\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}a=4\\b=-37\end{matrix}\right.\\\left\{{}\begin{matrix}a=-\frac{2}{3}\\b=-\frac{11}{9}\end{matrix}\right.\end{matrix}\right.\)
\(\Leftrightarrow...\)
