\(\frac{-2}{1.3}-\frac{2}{3.5}-...-\frac{2}{13.15}\)
\(=-\left(\frac{2}{1.3}+\frac{2}{3.5}+...+\frac{2}{13.15}\right)\)
\(=-\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{13}-\frac{1}{15}\right)\)
\(=-\left(1-\frac{1}{15}\right)\)
\(=\frac{-14}{15}\)