a) 86 + 357 + 14 = (86 + 14) + 357 = 457;
b) 72 + 69 + 128 = (72 + 128) + 69 = 269;
c) 25 . 5 . 4 . 27 . 2 = (25 . 4) . ( 5 . 2) . 27 = 100.10.27 = 27 000;
d) 28 . 64 + 28 . 36 = 28.(64 + 36) = 2800
a) 457 b) 269
c) 27000 d) 2800
-Học tốt-
a, (86+14) + 357 =100+357=457
b,(72+128)+69=200+69=269
c,25.4.5.2.27=100.10.27=27000
d,28.(64+36)=28.100=2800
câu cuối phải sửa thành d nhé
a) 86+357+14=(86+14)+357=100+357=457
b) 72+69+128=(72+128)+69=300+69=369
`c)25.5.4.27.2=(25.4).(2.5).27=100.10.27=27000
d) 28.64+28.36=(64+36).28=100.28=2800
a)86+357+14=(86+14)+357=100+357=457
b)72+69+128=(72+128)+69=200+69=269
c)25.5.4.27.2=(25.4).(5.4).27=100.10.27=27000
d)28.64+28.36=28.(54+36)=28.100=2800
hok tốt , có hứng thì kết bạn nha
a, 86+357+14
=(86+14)+357
=100+357
=457
b,72+69+128
=(72+128)+69
=200+69
=269
c,25.5.4.27.2
=(25.4).(5.2).27
=100.10.27
=27000
d,28.64+28.36
=28.(64+36)
=28.100
=2800