Đặt \(\dfrac{x}{3}=\dfrac{y}{4}=k\Rightarrow x=3k;y=4k\)
\(xy=48\\ \Rightarrow3k\cdot4k=48\\ \Rightarrow k^2=\dfrac{48}{12}=2\\ \Rightarrow\left[{}\begin{matrix}k=2\\k=-2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6;y=8\\x=-6;y=-8\end{matrix}\right.\)
Ta có:
\(\dfrac{x}{3}=\dfrac{y}{4}=k\)
\(\Rightarrow\left\{{}\begin{matrix}3k\\4k\end{matrix}\right.\)
mà \(xy=48\)
\(\Rightarrow3k.4k=48\)
\(12k^2=48\)
\(\Rightarrow k^{ }=\pm4\)
\(\Rightarrow\left\{{}\begin{matrix}\dfrac{x}{3}=\dfrac{y}{4}=4\\\dfrac{x}{3}=\dfrac{y}{4}=-4\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=12;y=16\\x=-12;-16\end{matrix}\right.\)
