\(16\frac{2}{7}\):\(\left(\frac{-3}{5}\right)\)+ \(28\frac{2}{7}\):\(\frac{3}{5}\)
= \(-16\frac{2}{7}\):\(\frac{3}{5}\)+\(28\frac{2}{7}\):\(\frac{3}{5}\)
=(\(-16\frac{2}{7}\)+\(28\frac{2}{7}\)) : \(\frac{3}{5}\)
=12 : \(\frac{3}{5}\)=12.\(\frac{5}{3}\)=20