Question

x : 2 = y : 3 và x . y = 9 ( . là giấu nhân ) Giúp e vs ạ bth toàn + - giờ có . k bt lm s 😭

Answer 1

Đặt \(\dfrac{x}{2}=\dfrac{y}{3}=k\)

=>x=2k; y=3k

xy=9

=>\(2k\cdot3k=9\)

=>\(k^2=\dfrac{9}{6}=\dfrac{3}{2}\)

TH1: \(k=\sqrt{\dfrac{3}{2}}=\dfrac{\sqrt{6}}{2}\)

\(x=2\cdot\dfrac{\sqrt{6}}{2}=\sqrt{6};y=3\cdot\dfrac{\sqrt{6}}{2}=\dfrac{3\sqrt{6}}{2}\)

TH2: \(k=-\dfrac{\sqrt{6}}{2}\)

=>\(x=2\cdot\dfrac{-\sqrt{6}}{2}=-\sqrt{6};y=3\cdot\dfrac{-\sqrt{6}}{2}=-\dfrac{3\sqrt{6}}{2}\)