Giải thích các bước giải:
$\begin{cases}\dfrac{x+1}{x-1}+\dfrac{3y}{y+2}=7\\\dfrac{2}{x-1}-\dfrac{5}{y+2}=4\end{cases}$
$\to \begin{cases}\dfrac{x-1+2}{x-1}+\dfrac{3(y+2)-6}{y+2}=7\\\dfrac{2}{x-1}-\dfrac{5}{y+2}=4\end{cases}$
$\to \begin{cases}1+\dfrac{2}{x-1}+3-\dfrac{6}{y+2}=7\\\dfrac{2}{x-1}-\dfrac{5}{y+2}=4\end{cases}$
$\to \begin{cases}\dfrac{2}{x-1}-\dfrac{6}{y+2}=3\\\dfrac{2}{x-1}-\dfrac{5}{y+2}=4\end{cases}$
$\to \begin{cases}\dfrac{1}{x-1}=\dfrac{9}{2}\\\dfrac{1}{y+2}=1\end{cases}$
$\to x=\dfrac{11}9, y=-1$
