7/8 : ( 2/9 - 1/18 ) + 7/8 ( 1/36 - 5/12)

$\dfrac{7}{8}$ $:$ $(\dfrac{2}{9}-\dfrac{1}{18})$ $+$ $\dfrac{7}{8}$ $.$ $(\dfrac{1}{36}-\dfrac{5}{12})$

$=$ $\dfrac{7}{8}$ $:$ $(\dfrac{4}{18}-\dfrac{1}{18})$ $+$ $\dfrac{7}{8}$ $.$ $(\dfrac{1}{36}-\dfrac{15}{36})$

$=$ $\dfrac{7}{8}$ $:$ $\dfrac{3}{18}$ $+$ $\dfrac{7}{8}$ $.$ $\dfrac{(-14)}{36}$ 

$=$ $\dfrac{7}{8}$ $:$ $\dfrac{1}{6}$ $+$ $\dfrac{7}{8}$ $.$ $\dfrac{(-7)}{18}$

$=$ $\dfrac{7}{8}$ $.$ $6$ $+$ $\dfrac{7}{8}$ $.$ $\dfrac{(-7)}{18}$

$=$ $\dfrac{7}{8}$ $.$ $(6 + $ $\dfrac{-7}{18})$

$=$ $\dfrac{7}{8}$ $.$ $(\dfrac{108}{18}+\dfrac{(-7)}{18})$

$=$ $\dfrac{7}{8}$ $.$ $\dfrac{101}{18}$ 

$=$ $\dfrac{707}{144}$