Выбери верные ответы

Выполни умножение алгебраических дробей.

1. \(\dfrac{2a}{a-b} \cdot \dfrac{a-b}{5b}=\) [ \(\frac{b}{a}\) | \(\frac{5b}{2a}\) | \(\frac{2a}{5b}\) | \(\frac{a}{b}\) ].
2. \(\dfrac{y-x}{3x} \cdot \dfrac{2x}{y-x}=\) [ \(\frac{2}{3}\) | \(\frac{3}{2}\) | \(\frac{2x}{3y}\) | \(\frac{3y}{2x}\) ].
3. \(\dfrac{3ab}{a+b} \cdot \dfrac{a+b}{12a}=\) [ \(\frac{4}{b}\) | \(\frac{b}{4}\) | \(\frac{3b}{4}\) | \(\frac{4b}{3}\) ].
4. \(\dfrac{x+y}{6xy} \cdot \dfrac{2x}{x+y}=\) [ \(3y\) | \(\frac{1}{3y}\) | \(y\) | \(\frac{y}{3}\) ].