\(\frac{3}{5}:\frac{7}{3}+\frac{3}{5}:\frac{7}{4}-1\frac{2}{3}\)

\(=\frac{3}{5}:\frac{7}{3}+\frac{3}{5}:\frac{7}{4}-\frac{5}{3}\)

\(=\frac{3}{5}.\frac{3}{7}+\frac{3}{5}.\frac{4}{7}-\frac{5}{3}\)

\(=\frac{3}{5}\left(\frac{3}{7}+\frac{4}{7}\right)-\frac{5}{3}\)

\(=\frac{3}{5}.1-\frac{5}{3}\)

\(=\frac{3}{5}-\frac{5}{3}\)

\(=-\frac{16}{15}\)