a: \(\dfrac{2}{3}+\dfrac{1}{5}+\dfrac{-5}{3}+\dfrac{3}{5}+1\)
\(=\left(\dfrac{2}{3}-\dfrac{5}{3}\right)+1+\left(\dfrac{1}{5}+\dfrac{3}{5}\right)\)
\(=-\dfrac{3}{3}+1+\dfrac{4}{5}=\dfrac{4}{5}\)
a: \(\dfrac{7}{10}+\dfrac{-5}{6}-\dfrac{-3}{4}-\dfrac{1}{5}+\dfrac{-2}{3}\)
\(=\left(\dfrac{7}{10}-\dfrac{1}{5}\right)+\left(\dfrac{-5}{6}+\dfrac{3}{4}-\dfrac{2}{3}\right)\)
\(=\dfrac{7-2}{10}+\dfrac{-10+9-8}{12}\)
\(=\dfrac{5}{10}+\dfrac{-9}{12}=\dfrac{1}{2}-\dfrac{3}{4}=\dfrac{-1}{4}\)
a: \(\dfrac{5}{19}+\dfrac{-5}{3}+\dfrac{-21}{37}+\dfrac{14}{19}+\dfrac{-16}{37}\)
\(=\left(\dfrac{5}{19}+\dfrac{14}{19}\right)+\left(\dfrac{-21}{37}-\dfrac{16}{37}\right)+\dfrac{-5}{3}\)
\(=\dfrac{19}{19}+\dfrac{-37}{37}+\dfrac{-5}{3}=\dfrac{-5}{3}\)
