解:$$\begin{cases} 2\left( x+y \right) +3\left( x-y \right) =5 \\ 5\left( x+y \right) +7\left( x-y \right) =12 \end{cases}\Rightarrow \begin{cases} 5x-y=5 \\ 12x-2y=12 \end{cases}\Rightarrow \begin{cases} 5x-y=5 \\ 6x-y=6 \end{cases}\\ \Rightarrow x=1,y=0\Rightarrow 2x+y=2$$,故選\(\bbox[red,2pt]{(A)}\)。