Question

Answer 1

a: Đặt \(\dfrac{x}{2}=\dfrac{y}{3}=k\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=2k\\y=3k\end{matrix}\right.\)

Ta có: xy=18

\(\Leftrightarrow6k^2=18\)

\(\Leftrightarrow k^2=3\)

Trường hợp 1: \(k=\sqrt{3}\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=2k=2\sqrt{3}\\y=3k=3\sqrt{3}\end{matrix}\right.\)

Trường hợp 2: \(k=-\sqrt{3}\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=2k=-2\sqrt{3}\\y=3k=-3\sqrt{3}\end{matrix}\right.\)