`{(y-x=2),(5x-3y=10):}`
`<=>{(y=2+x),(5x-3(2+x)=10):}`
`<=> {(y=2+x),(5x-6-3x=10):}`
`<=> {(y=2+x),(2x=10+6=16):}`
`<=>{(x=8),(y=2+8=10):}`
\(\left\{{}\begin{matrix}y-x=2\\5x-3y=10\end{matrix}\right.\\ =>\left\{{}\begin{matrix}-x+y=2\\5x-3y=10\end{matrix}\right.\\ =>\left\{{}\begin{matrix}-3x+3y=6\\5x-3y=10\end{matrix}\right.\\ =>\left\{{}\begin{matrix}2x=16\\-x+y=2\end{matrix}\right.\\ =>\left\{{}\begin{matrix}x=8\\-8+y=2\end{matrix}\right.\\ =>\left\{{}\begin{matrix}x=8\\y=10\end{matrix}\right.\)
Vậy \(\left(x;y\right)=\left(8;10\right)\)
=>x-y=-2 và 5x-3y=10
=>5x-5y=-10 và 5x-3y=10
=>-2y=-20 và x-y=-2
=>y=10 và x=-2+y=-2+10=8
