a: \(A=\dfrac{-3}{17}+\dfrac{2}{3}+\dfrac{3}{17}=\dfrac{2}{3}\)
b: \(B=\dfrac{-1}{6}+\dfrac{5}{12}+\dfrac{7}{12}=\dfrac{-1}{6}+1=\dfrac{5}{6}\)
c: \(C=\left(-\dfrac{5}{7}-\dfrac{2}{7}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\dfrac{-1}{5}=\dfrac{-1}{5}\)
d: \(D=\left(-\dfrac{3}{31}-\dfrac{28}{31}\right)+\left(-\dfrac{6}{17}+\dfrac{-11}{17}\right)+\left(\dfrac{1}{25}-\dfrac{4}{25}\right)=-2-\dfrac{3}{25}=-\dfrac{53}{25}\)
\(a.A=\dfrac{-3}{17}+\dfrac{3}{17}+\dfrac{2}{3}=0+\dfrac{2}{3}=\dfrac{2}{3}\)
\(b.B=-\dfrac{1}{6}+\dfrac{5}{12}+\dfrac{7}{12}=-\dfrac{1}{6}+\dfrac{12}{12}=-\dfrac{1}{6}+1=\dfrac{5}{6}\)
\(c.C=-\dfrac{5}{7}+-\dfrac{2}{7}+\dfrac{3}{4}+\dfrac{1}{4}+-\dfrac{1}{5}=-1+1+-\dfrac{1}{5}=-\dfrac{1}{5}\)
\(d.D=-\dfrac{3}{31}+-\dfrac{28}{31}+-\dfrac{6}{17}+-\dfrac{11}{17}+\dfrac{1}{25}+-\dfrac{1}{5}=-1-1-\dfrac{4}{25}=-2-\dfrac{4}{25}=-\dfrac{54}{25}\)
\(A=\left(\dfrac{-3}{17}+\dfrac{3}{17}\right)+\dfrac{2}{3}\\ A=0+\dfrac{2}{3}=\dfrac{2}{3}\\ B=\dfrac{-1}{6}+\left(\dfrac{5}{12}+\dfrac{7}{12}\right)\\ B=\dfrac{-1}{6}+1=\dfrac{-7}{6}\\ C=\left(\dfrac{-5}{7}+\dfrac{-2}{7}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\dfrac{-1}{5}\\ C=-1+1+\dfrac{-1}{5}=\dfrac{-1}{5}\\ D=\left(\dfrac{-3}{31}+\dfrac{-28}{31}\right)+\left(\dfrac{-6}{17}+\dfrac{-11}{17}\right)+\left(\dfrac{1}{25}+\dfrac{-1}{5}\right)\\ D=-1+\left(-1\right)+\left(\dfrac{1}{25}+\dfrac{-5}{25}\right)\\ D=\left(-1\right)+\left(-1\right)+\dfrac{-4}{25}\\ D=-2\dfrac{-4}{25}=\dfrac{\left(-2\right)\times25+\left(-4\right)}{25}=\dfrac{-54}{25}\)