Sửa đề: \(\begin{cases}3\left(x-1\right)+\frac{2}{x+2y}=4\\ 4\left(x+1\right)-\frac{1}{x+2y}=9\end{cases}\)
ĐKXĐ: x<>-2y
Ta có: \(\begin{cases}3\left(x-1\right)+\frac{2}{x+2y}=4\\ 4\left(x-1\right)-\frac{1}{x+2y}=9\end{cases}\)
=>\(\begin{cases}3\left(x-1\right)+\frac{2}{x+2y}=4\\ 8\left(x-1\right)-\frac{2}{x+2y}=18\end{cases}\Rightarrow\begin{cases}3\left(x-1\right)+\frac{2}{x+2y}+8\left(x-1\right)-\frac{2}{x+2y}=4+18=22\\ 3\left(x-1\right)+\frac{2}{x+2y}=4\end{cases}\)
=>\(\begin{cases}11\left(x-1\right)=22\\ \frac{2}{x+2y}=4-3\left(x-1\right)\end{cases}\Rightarrow\begin{cases}x-1=2\\ \frac{2}{x+2y}=4-3\cdot2=4-6=-2\end{cases}\)
=>\(\begin{cases}x=3\\ x+2y=-1\end{cases}\Rightarrow\begin{cases}x=3\\ 2y=-1-x=-1-3=-4\end{cases}\Rightarrow\begin{cases}x=3\\ y=-2\end{cases}\) (nhận)
