\(60\frac{7}{13}x+50\frac{8}{13}x-11\frac{2}{13}x=x.\left(60\frac{7}{13}+50\frac{8}{13}-11\frac{2}{13}\right)\)
\(=x.\left(60+\frac{7}{13}+50+\frac{8}{13}-11-\frac{2}{13}\right)\)
\(=-8\frac{1}{7}.\left(99+1\right)\)
\(=\frac{-57}{7}.100=\frac{-5700}{7}\)