\(=\dfrac{7}{18}.\dfrac{-12}{23}-\dfrac{7}{18}.\dfrac{4}{5}+\dfrac{7}{18}.\dfrac{8}{30}+\dfrac{7}{18}.\dfrac{35}{23}\)
\(=\dfrac{7}{18}.\left(\dfrac{-12}{23}+\dfrac{35}{23}\right)+\dfrac{7}{18}.\left(\dfrac{4}{5}-\dfrac{8}{30}\right)\)
\(=\dfrac{7}{18}.1+\dfrac{7}{18}.\dfrac{8}{15}\)
\(=\dfrac{7}{18}+\dfrac{28}{135}\)
\(=\dfrac{161}{270}\)