a,29.(87-23)+64.71=29.64+64.71=64.(29+71)=64.100=6400
b,19.(27+20)+47.81=19.47+47.81=47.(19+81)=47.100=4700
c,87.(23+70)+13.93=87.93+13.93=93.(87+13)=93.100=9300
tick nha bạn
a.65.35
b.86.28
c.172.03
chúc hok tốt! =))
29.87 - 29.23 + 64.71
= 29.(87 - 23) + 64.71
= 29. 64 + 64.71
= (29+71).64
= 100.64
= 6400
19.27 + 47.81 +19.20
= 19.(27+20) +47.81
= 19. 47 +47.81
= (19+81).47
= 100.47
= 4700
87.23 +13.93 + 70.87
= 87.(23 + 70) + 13.93
= 87. 93 + 13.93
= (87 + 13) .93
= 100.93
= 9300