BT = \(\frac{5}{9}\left(\frac{2}{22}-\frac{5}{22}\right)+\frac{5}{9}\left(\frac{1}{15}-\frac{10}{15}\right)\)
= \(\frac{5}{9}.\frac{-3}{22}+\frac{5}{9}.\frac{-3}{5}\)
= \(\frac{-5}{3}\left(\frac{1}{22}+\frac{1}{5}\right)\) = \(\frac{-5}{3}\left(\frac{5}{110}+\frac{22}{110}\right)\) = \(\frac{-5}{3}.\frac{27}{110}=\frac{-9}{22}\)
\(\frac{5}{9}.\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{5}{9}.\left(\frac{1}{15}-\frac{2}{3}\right)\)
= \(\frac{5}{9}.\left(-\frac{3}{22}\right)+\frac{5}{9}.\left(-\frac{3}{5}\right)\)
= \(\frac{5}{9}.\left(-\frac{3}{22}+\frac{-3}{5}\right)\)
= \(\frac{5}{9}.\left(-\frac{81}{110}\right)\)
= \(-\frac{9}{22}\)
