Question

:D

Answer 1

`{(x/3=y/5),(x-y=6):}`

`<=>{(x=(3y)/5),(x-y=6):}`

`<=>{(x-(3y)/5=0),(x-y=6):}`

`<=>{(2/5y=-6),(x=(3y)/5):}`

`<=>{(y=-15),(x=(3y)/5=-9):}`

Vậy `(x,y)=(-9,-15)`

Answer 2

\(\left\{{}\begin{matrix}\dfrac{x}{3}=\dfrac{y}{5}\\x-y=6\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}5x=3y\\x-y=6\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}5x-3y=0\left(1\right)\\5x-5y=30\left(2\right)\end{matrix}\right.\)

Lấy \(\left(1\right)-\left(2\right)\Rightarrow2y=-30\Rightarrow y=-15\Rightarrow x=6-15=-9\)