\(\dfrac{-3}{8}.\dfrac{2}{7}+\dfrac{-3}{8}.\dfrac{5}{7}+\left|\dfrac{-7}{8}\right|\)
\(=\dfrac{-3}{8}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{7}{8}\)
\(=\dfrac{-3}{8}+\dfrac{7}{8}\)
\(=\dfrac{1}{2}\)
\(=\dfrac{-3}{8}\cdot\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{7}{8}\\ =-\dfrac{3}{8}\cdot1+\dfrac{7}{8}\\ =-\dfrac{3}{8}+\dfrac{7}{8}\\ =\dfrac{4}{8}=\dfrac{1}{2}\)
\(\dfrac{-3}{8}.\dfrac{2}{7}+\dfrac{-3}{8}.\dfrac{5}{7}+\left|\dfrac{-7}{8}\right|\)
\(=\dfrac{-3}{8}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{7}{8}\)
\(=\dfrac{-3}{8}.1+\dfrac{7}{8}\)
\(=\dfrac{-3}{8}+\dfrac{7}{8}\)
\(=\dfrac{4}{8}=\dfrac{1}{2}\)