$(4\dfrac{3}{17}-3\dfrac{4}{7}+5\dfrac{6}{13})-(2\dfrac{3}{7}-1\dfrac{7}{13})$
$=\dfrac{71}{17}-\dfrac{25}{7}+\dfrac{71}{13}-\dfrac{17}{7}+\dfrac{20}{13}$
$=\dfrac{71}{17}-\dfrac{25}{7}-\dfrac{17}{7}+\dfrac{71}{13}+\dfrac{20}{13}$
$=\dfrac{71}{17}-\dfrac{42}{7}+\dfrac{91}{13}$
$=\dfrac{71}{17}-6+7$
$=\dfrac{88}{17}$
$(3\dfrac{5}{12}-1\dfrac{8}{9}):(0,25-2\dfrac{1}{12})$
$=(\dfrac{41}{12}-\dfrac{17}{9}):(\dfrac{1}{4}-\dfrac{25}{12})$
$=\dfrac{55}{36}:\dfrac{-11}{6}$
$=\dfrac{55}{36}.\dfrac{-6}{11}$
$=\dfrac{-5}{6}$
