\(\left\{{}\begin{matrix}2\left(x+y\right)^2-3\left(x+y\right)-9=0\\x-y=5\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x+y=3\\x+y=-\frac{3}{2}\end{matrix}\right.\)
TH1: \(\left\{{}\begin{matrix}x+y=3\\x-y=5\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=4\\y=-1\end{matrix}\right.\)
TH2: \(\left\{{}\begin{matrix}x+y=-\frac{3}{2}\\x-y=5\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=\frac{7}{4}\\y=-\frac{13}{4}\end{matrix}\right.\)
Câu 2:
\(\left\{{}\begin{matrix}5\left(x-y\right)^2+3\left(x-y\right)-8=0\\2x+3y=12\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x-y=1\\x-y=-\frac{8}{5}\end{matrix}\right.\)
TH1: \(\left\{{}\begin{matrix}x-y=1\\2x+3y=12\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=3\\y=2\end{matrix}\right.\)
Th2: \(\left\{{}\begin{matrix}x-y=-\frac{8}{5}\\2x+3y=12\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=\frac{36}{25}\\y=\frac{76}{25}\end{matrix}\right.\)
