Question

Giải hộ mình câu 4

Answer 1

Câu 5:

Áp dụng tc dtsbn:

\(5x=3y\Leftrightarrow\dfrac{x}{3}=\dfrac{y}{5}\Leftrightarrow\dfrac{x^2}{9}=\dfrac{y^2}{25}=\dfrac{x^2-y^2}{9-25}=\dfrac{-4}{-16}=\dfrac{1}{4}\\ \Leftrightarrow\left\{{}\begin{matrix}x^2=\dfrac{9}{4}\\y^2=\dfrac{25}{4}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\pm\dfrac{3}{2}\\y=\pm\dfrac{5}{2}\end{matrix}\right.\)