\(B=\left(-\frac{5}{9}\right).\frac{3}{11}+\left(-\frac{13}{18}\right).\frac{3}{11}\)
\(=\frac{3}{11}.\left[\left(-\frac{5}{9}\right)+\left(-\frac{13}{18}\right)\right]\)
\(=\frac{3}{11}.\left[\left(-\frac{10}{18}\right)+\left(-\frac{13}{18}\right)\right]\)
\(=\frac{3}{11}.\frac{-23}{18}\)
\(=-\frac{23}{66}\)
\(B=\left(-\frac{5}{9}\right).\frac{3}{11}+\left(-\frac{13}{18}\right).\frac{3}{11}\)
\(B=\left[-\frac{5}{9}+\left(-\frac{13}{18}\right)\right].\frac{3}{11}\)
\(B=-\frac{23}{18}.\frac{3}{11}\)
\(B=-\frac{23}{66}\)