$(\dfrac{-5}{6})-(\dfrac{-1}{4})$=

$\dfrac{(\dfrac{-3}{5})}{(\dfrac{-3}{4})}$=

$\dfrac{1}{2} : \dfrac{1}{3}$=

$\dfrac{5}{4}-\dfrac{8}{5}$=

$\dfrac{(\dfrac{-1}{2})}{(\dfrac{-2}{7})}$=

$\dfrac{9}{5} : \dfrac{7}{6}$=

$(\dfrac{-6}{5})\times(\dfrac{-7}{6})$=

$\dfrac{8}{5}\times\dfrac{8}{5}$=

$(\dfrac{-8}{5})-\dfrac{4}{5}$=

$\dfrac{7}{9}\times\dfrac{5}{2}$=