1: \(=\left(\dfrac{6}{5}+\dfrac{4}{5}\right)+\left(-\dfrac{1}{4}-\dfrac{3}{4}\right)=2-1=1\)
2: \(=\dfrac{7}{9}+\dfrac{2}{9}-\dfrac{5}{12}-\dfrac{7}{12}=1-1=0\)
3: \(=\dfrac{-4}{15}-\dfrac{11}{15}+\dfrac{5}{13}+\dfrac{8}{13}=-1+1=0\)
4: \(=\dfrac{9}{15}+\dfrac{6}{15}-\dfrac{7}{13}-\dfrac{6}{13}=1-1=0\)
5: \(=3-1=2\)