a)\(\dfrac{-2}{7}\)+\(\dfrac{2}{7}\):\(\dfrac{3}{5}\)

=\(\dfrac{-2}{7}\)+\(\dfrac{2}{7}\).\(\dfrac{5}{3}\)

=\(\dfrac{-2}{7}\)+\(\dfrac{10}{21}\)

=\(\dfrac{4}{21}\)

b) \(\dfrac{-8}{19}\)+\(\dfrac{-4}{21}\)-\(\dfrac{17}{21}\)+\(\dfrac{27}{19}\)

=\(\dfrac{-8}{19}\)+\(\dfrac{27}{19}\)-\(\dfrac{17}{21}\)+\(\dfrac{-4}{21}\)

=\(\left(\dfrac{-8+27}{19}\right)\)-\(\left(\dfrac{17+-4}{21}\right)\)

=\(\dfrac{19}{19}\)-\(\dfrac{-21}{21}\)

=1-1

=0

c)\(\dfrac{6}{5}\).\(\dfrac{3}{13}\)-\(\dfrac{6}{5}\).\(\dfrac{16}{13}\)

=\(\dfrac{6}{5}\).\(\left(\dfrac{3}{13}-\dfrac{16}{13}\right)\)

=\(\dfrac{6}{5}\).\(\left(\dfrac{3-6}{13}\right)\)

=\(\dfrac{6}{5}\).\(\left(\dfrac{-13}{13}\right)\)

=\(\dfrac{6}{5}\).(-1)

=\(\dfrac{-6}{5}\)