a)5*7+ \frac{19}{10}=35$\frac{19}{10}=36\frac{9}{10}$
b)6*7-3/3 = 42-1= 41
c)14-9/9+6*3 =14-1+18= 13+18=31
d)21*1/2+7/7 =10$\frac{1}{2}+1=11\frac{1}{2}$
e)8/9-4:16-10/12 =\frac{8}{9} - \frac{1}{4} -\frac{10}{12}=
\frac{32}{36} -\frac{9}{36} - \frac{30}{36} = \frac{-7}{36}
f)(14*81-17/21):8/3= (1134 - \frac{17}{21}) : \frac{8}{3} =
1133 \frac{4}{21} : \frac{8}{3}= \frac{23797}{21} * \frac{3}{8}=
\frac{23797}{7} * \frac{1}{8} =\frac{23797}{56} =424$\frac{7}{8}$ = 424,875