70. a) -4,8*8,9+8,9*(-5,2)=-4,8*8,9-8,9*5,2=8,9(-4,8-5,2)=8,9*(-10)=-(8,9*10)=-89
b) -1,2*(-7*[tex] \frac{9}{13} [/tex])-(-1,2)*2*[tex] \frac{4}{13} [/tex]=[tex]- \frac{6}{5}*(- \frac{63}{13})+1,2*2* \frac{4}{13}= \frac{378}{65}+ \frac{6}{5}*2* \frac{4}{3}= \frac{378}{65}+ \frac{48}{65}= \frac{378+48}{65} = [/tex][tex] \frac{426}{65}[/tex];[tex]6 \frac{36}{65}[/tex]; ≈6,55385
c) [tex]-2 \frac{3}{7}*2 \frac{4}{5}+(2 \frac{3}{7})*4 \frac{1}{5}=- \frac{17}{7}*\frac{14}{5}+(-\frac{17}{7})*\frac{21}{5}=-17*\frac{2}{5}-17*\frac{3}{5}= [/tex][tex]-\frac{34}{5}-\frac{51}{5}=\frac{-34-51}{5}=\frac{-85}{5}=-\frac{85}{5}=-17[/tex]
d) [tex]-32,3*7 \frac{10}{13}+2 \frac{3}{13}*(-32,3)=- \frac{323}{10}* \frac{101}{13}+ \frac{29}{13}*(- \frac{323}{10})=[/tex][tex]- \frac{32623}{130}- \frac{9367}{130}= \frac{-32623-9367}{130}= \frac{-41990}{130}=- \frac{41990}{130}=-323 [/tex]
