-10/11.8/9+7/18.10/11
=10/11.-8/9+7/18.10/11
=10/11.(-8/9+7/18)
=10/11.-1/2
=-5/11
\(-\frac{10}{11}\cdot\frac{8}{9}+\frac{7}{18}\cdot\frac{10}{11}\)
\(=\frac{10}{11}\cdot\frac{-8}{9}+\frac{7}{18}\cdot\frac{10}{11}\)
\(=\frac{10}{11}\cdot\left(-\frac{8}{9}+\frac{7}{18}\right)\)
\(=\frac{10}{11}\cdot\frac{-1}{2}\)
\(=-\frac{5}{11}\)