\(a,\dfrac{3}{8}+\dfrac{5}{8}=\dfrac{3+5}{8}=\dfrac{8}{8}=1\\ b,\dfrac{1}{6}+\dfrac{2}{5}=\dfrac{5}{30}+\dfrac{12}{30}=\dfrac{5+12}{30}=\dfrac{17}{30}\\ c,3+\dfrac{-5}{6}=\dfrac{18}{6}+\dfrac{-5}{6}=\dfrac{18+\left(-5\right)}{6}=\dfrac{13}{6}\\ d,2\dfrac{4}{5}+1\dfrac{3}{5}=\dfrac{14}{5}+\dfrac{8}{5}=\dfrac{14+8}{5}=\dfrac{22}{5}\)
\(a.\dfrac{3}{8}+\dfrac{5}{8}=\dfrac{8}{8}=1\)
\(b.\dfrac{1}{6}+\dfrac{2}{5}=\dfrac{5}{30}+\dfrac{12}{30}=\dfrac{17}{30}\)
\(c.3+\dfrac{-5}{6}=\dfrac{18}{6}+\dfrac{-5}{6}=\dfrac{13}{6}\)
\(d.2\dfrac{4}{5}+1\dfrac{3}{5}=\left[\left(2+1\right)\left(\dfrac{4}{5}+\dfrac{3}{5}\right)\right]=3\dfrac{7}{5}\)
