Question

ajutor ex 70 pls dau coroana

Answer 1

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*$\frac{9}{13}$)-(-1,2)*2*$\frac{4}{13}$=$- \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} =$$\frac{426}{65}$;$6 \frac{36}{65}$; ≈6,55385

c) $-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}=$$-\frac{34}{5}-\frac{51}{5}=\frac{-34-51}{5}=\frac{-85}{5}=-\frac{85}{5}=-17$

d) $-32,3*7 \frac{10}{13}+2 \frac{3}{13}*(-32,3)=- \frac{323}{10}* \frac{101}{13}+ \frac{29}{13}*(- \frac{323}{10})=$$- \frac{32623}{130}- \frac{9367}{130}= \frac{-32623-9367}{130}= \frac{-41990}{130}=- \frac{41990}{130}=-323$