Выполни задание
\(\cfrac{a}{b}=\cfrac{c}{d}\) , \(\cfrac{d}{b}=\cfrac{c}{a}\) , \(ad=bc\) , \(a=\cfrac{bc}{d}\) , \(\cfrac{a}{c}=\cfrac{b}{d}\) .

Найди \(x\) .

1. \(3,7x=7,4\cdot 9\) ;

2. \(2\dfrac{1}{2}\cdot 3\dfrac{1}{3}=8\dfrac{1}{3}x \) ;

3. \(\dfrac{x}{0,45}=\dfrac{0,25}{0,9}\) .