Вычисли

а) \(\cfrac{3}{5}\cdot 2=\cfrac{3}{5}\cdot \cfrac{2}{1}=\cfrac{3\cdot 2}{5\cdot 1}=\cfrac{6}{5}\) ;

б) \(\cfrac{1}{15}\cdot 4=\) [ ] \(\cdot\) [ ] \(=\) [ ] \(=\) [ ];

в) \(\cfrac{3}{7}\cdot 2=\) [ ] \(\cdot\) [ ] \(=\) [ ] \(=\) [ ];

г) \(\cfrac{5}{9}\cdot 3=\) [ ] \(\cdot\) [ ] \(=\) [ ] \(=\) [ ];

д) \(5\cdot \cfrac{9}{10}=\) [ ] \(\cdot\) [ ] \(=\) [ ] \(=\) [ ];

е) \(6\cdot \cfrac{7}{9}=\) [ ] \(\cdot\) [ ] \(=\) [ ] \(=\) [ ].