\(a,\dfrac{2}{3}-\dfrac{3}{9}=\dfrac{6}{9}-\dfrac{3}{9}=\dfrac{3}{9}=\dfrac{1}{3}\\ b,\dfrac{7}{5}-\dfrac{15}{25}=\dfrac{7}{5}-\dfrac{3}{5}=\dfrac{4}{5}\\ c,\dfrac{3}{2}-\dfrac{4}{8}=\dfrac{3}{2}-\dfrac{1}{2}=\dfrac{2}{2}=1\\ d,\dfrac{11}{4}-\dfrac{6}{8}=\dfrac{11}{4}-\dfrac{3}{4}=\dfrac{8}{4}=2\)