\(\dfrac{2}{5}+\left(-\dfrac{4}{3}\right)+\left(-\dfrac{1}{2}\right)\)
\(=\dfrac{2}{5}-\dfrac{4}{3}-\dfrac{1}{2}\)
\(=\dfrac{6}{15}-\dfrac{20}{15}-\dfrac{1}{2}\)
\(=\dfrac{-14}{15}-\dfrac{1}{2}\)
\(=\dfrac{-28}{30}-\dfrac{15}{30}\)
\(=\dfrac{-43}{30}\)
\(\dfrac{2}{5}+\left(\dfrac{-4}{3}\right)+\left(-\dfrac{1}{2}\right)\)
\(=\dfrac{12}{30}-\dfrac{40}{30}-\dfrac{15}{30}\)
\(=-\dfrac{28}{30}-\dfrac{15}{30}\)
\(=\dfrac{-43}{30}\)