$A=\dfrac{-9}{14}+\dfrac57 : 5-\dfrac{1}{18.(-3).2}$
$=\dfrac{-9}{14}+\dfrac57 .\dfrac15-\dfrac{1}{-108}$
$=\dfrac{-9}{14}+\dfrac17+\dfrac{1}{108}$
$=\dfrac{-9.54}{756}+\dfrac{108}{756}+\dfrac{7}{756}$
$=\dfrac{-486+108+7}{756}$
$=\dfrac{-371}{756}$
$=\dfrac{-53}{108}$