Question

\(\left\{{}\begin{matrix}\dfrac{x}{y}=\dfrac{2}{3}\\x+y-10=0\end{matrix}\right.\)

Answer 1

\(\Leftrightarrow\left\{{}\begin{matrix}3x-2y=0\\3x+3y=30\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-5y=-30\\x+y=10\end{matrix}\right.\Leftrightarrow\left(x,y\right)=\left(4;6\right)\)

Answer 2

cách khác bạn kham khảo nhé

\(\left\{{}\begin{matrix}\dfrac{x}{y}=\dfrac{2}{3}\\x+y-10=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x}{2}=\dfrac{y}{3}\\x+y=10\end{matrix}\right.\)

Theo tc dãy tỉ số bằng nhau

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{x+y}{2+3}=\dfrac{10}{5}=2\Rightarrow x=4;y=6\)