a: \(x+\dfrac{1}{3}=\dfrac{2}{5}-\left(-\dfrac{1}{3}\right)\)
=>\(x+\dfrac{1}{3}=\dfrac{2}{5}+\dfrac{1}{3}\)
=>\(x=\dfrac{2}{5}\)
b: \(-\dfrac{3}{7}-x=\dfrac{4}{5}+\dfrac{-2}{3}\)
=>\(-\dfrac{3}{7}-x=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\)
=>\(x=-\dfrac{3}{7}-\dfrac{2}{15}=-\dfrac{45}{105}-\dfrac{14}{105}=-\dfrac{59}{105}\)
c: \(-\dfrac{5}{8}-x=-\dfrac{3}{20}-\left(-\dfrac{1}{6}\right)\)
=>\(-\dfrac{5}{8}-x=-\dfrac{3}{20}+\dfrac{1}{6}\)
=>\(x=-\dfrac{5}{8}+\dfrac{3}{20}-\dfrac{1}{6}=-\dfrac{75}{120}+\dfrac{18}{120}-\dfrac{20}{120}=-\dfrac{77}{120}\)
d: \(\dfrac{5}{12}-\left(\dfrac{3}{8}-x\right)=-\dfrac{5}{6}\)
=>\(\dfrac{3}{8}-x=\dfrac{5}{12}+\dfrac{5}{6}=\dfrac{5}{12}+\dfrac{10}{12}=\dfrac{15}{12}=\dfrac{5}{4}\)
=>\(x=\dfrac{3}{8}-\dfrac{5}{4}=-\dfrac{7}{8}\)
