2 câu trả lời
Ta đặt $k=\dfrac{x}{2}=\dfrac{y}{5}$
$⇒x=2k$ và $y=5k$
$⇒2k.5k=10$
$⇒10k^2=10$
$⇒k^2=1$
$⇒k=±1$
\(⇒\left[ \begin{array}{l}k=1⇒\left \{ {{x=2} \atop {y=5}} \right.\\k=-1⇒\left \{ {{x=-2} \atop {y=-5}} \right.\end{array} \right.\)
$\dfrac{x}{2}=\dfrac{y}{5}$ và $x.y=10$
Ta có:
$\dfrac{x}{2}=\dfrac{y}{5}=\dfrac{x.y}{2.5}=\dfrac{10}{10}=1$
$\dfrac{x}{2}=1⇒x=2.1=2$
$\dfrac{y}{5}=1⇒y=5.1=5$
