a)  \(\frac{6}{5}+\frac{4}{3}.\frac{21}{8}-\frac{13}{10}=\frac65+\frac72-\frac{13}{10}=\frac{12}{10}+\frac{35}{10}-\frac{13}{10}=\frac{17}{5}\)

b)   \(\frac{- 11}{12}.\frac{18}{25}+\frac{- 11}{12}.\frac{7}{25}+\frac{11}{12}=\frac{-11}{12}+\left(\frac{18}{25}+\frac{7}{25}-1\right)=\frac{-11}{12}*0_{}=0\)

c)   \(12,89+27,11-43,65+\left(\right.-56,35\left.\right)=\left(12,89+27,11\right)-\left(43,65+56,35\right)=40-100=-60\);

d)   \(1\frac{13}{15}.\left(0,5\right)^2.3+\left(\frac{8}{15}-1\frac{19}{60}\left.\right):1\frac{23}{24}=\frac{28}{15}*\frac14*3+\left(\frac{8}{15}-\frac{79}{60}\right):\frac{47}{24}=\frac75+\left(\frac{-47}{60}\right):\frac{47}{24}=\frac75+\left(\frac{-2}{5}\right)\right.=1\)