Có \(2x=3y\Leftrightarrow\frac{x}{3}=\frac{y}{2}\Rightarrow\frac{x^3}{27}=\frac{y^2}{4}\Rightarrow\frac{x^3}{27}=\frac{3y^2}{12}\)
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\frac{x^3}{27}=\frac{3y^2}{12}=\frac{x^3+3y^2}{27}=\frac{84}{39}=\frac{28}{13}\)
Do đó:
\(\frac{x^3}{27}=\frac{28}{13}\Leftrightarrow\frac{x}{3}=\frac{28}{13}\Rightarrow x=\frac{3.28}{13}=\frac{84}{13}\)
\(\frac{3y^2}{12}=\frac{28}{13}\Leftrightarrow\frac{y^2}{4}=\frac{28}{13}\Rightarrow\frac{y}{2}=\frac{28}{13}\Rightarrow y=\frac{2.28}{13}=\frac{56}{13}\)
Vậy x = \(\frac{84}{13}\); y = \(\frac{56}{13}\)
