\(\dfrac{-2}{5}+\left(\dfrac{4}{6}-\dfrac{1}{15}\right)-\dfrac{-1}{10}\\ =\dfrac{-2}{5}+\dfrac{3}{5}+\dfrac{1}{10}\\ =\dfrac{1}{5}+\dfrac{1}{10}\\ =\dfrac{3}{10}\\ \dfrac{1}{2}-\left(\dfrac{-7}{3}+\dfrac{2}{5}\right)+\dfrac{1}{8}\\ =\dfrac{1}{2}+\dfrac{29}{15}+\dfrac{1}{8}\\ =\dfrac{73}{30}\\ =\dfrac{73}{30}+\dfrac{1}{8}\\ =\dfrac{307}{120}\)
\(-\dfrac{2}{5}+\left(\dfrac{4}{6}-\dfrac{1}{15}\right)-\left(-\dfrac{1}{10}\right)\)
\(=-\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{1}{10}\)
\(=\dfrac{1}{5}+\dfrac{1}{10}\)
\(=\dfrac{2}{10}+\dfrac{1}{10}=\dfrac{3}{10}\)
\(\dfrac{1}{2}-\left(-\dfrac{7}{3}+\dfrac{2}{5}\right)+\dfrac{1}{8}\)
\(=\dfrac{1}{2}+\dfrac{29}{15}+\dfrac{1}{8}\)
\(=\dfrac{73}{30}+\dfrac{1}{8}=\dfrac{307}{120}\)