Выполни действия

1. \(\dfrac{a+b}{2x}+\dfrac{a-b}{2x}=\) [ ];
2. \(\dfrac{9+7y}{a+b}-\dfrac{5y+5}{a+b}=\) [ ];
3. \(\dfrac{2c}{c-x}-\dfrac{c}{c-x}-\dfrac{x}{c-x}=\) [ ].