\(\frac{x}{3}=\frac{y}{4}\rightarrow x=3k;y=4k\)
Thay x=3k; y=4k vào bt có:
\(2\left(3k\right)^2-3\left(4k\right)^2=-120\)
\(\rightarrow18k^2-48k^2=-120\)
\(\rightarrow-30k^2=-120\)
\(\rightarrow k^2=4\)
\(\Rightarrow k=\left\{2;-2\right\}\)
\(\Rightarrow\left[{}\begin{matrix}x=2.3=6\\y=2.4=8\end{matrix}\right.\) hoặc \(\left[{}\begin{matrix}x=-2.3=-6\\y=-2.4=-8\end{matrix}\right.\)
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