Question

\(\dfrac{x}{5}=\dfrac{y}{3}\)va x² - y² = 4

tim x va y nha cac bn!!!

Answer 1

\(\dfrac{x}{5}=\dfrac{y}{3}\Leftrightarrow\dfrac{x^2}{25}=\dfrac{y^2}{9}\)

Áp dụng t/c dãy tỉ số bằng nhau ta có :

\(\dfrac{x^2}{25}=\dfrac{y^2}{9}=\dfrac{x^2-y^2}{25-9}=\dfrac{4}{16}=\dfrac{1}{4}\)

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

Vậy ..