a26+17+23+14=[26+14]+[17+23]=40+40=80,b46+82+18+54=[46+54]+[82+18]=100+100=200,c37-5+37-7=37-[5+7]=37-12=25
Bài 1: Tính nhanh:
a) 26 + 17 + 23 + 14
= (26 + 14) + (17 + 23)
= 40 + 40
= 80
b) 46 + 82 + 18 + 54
= (46 + 54) + (82 + 18)
= 100 + 100
= 200
c) 37 - 5 + 37 -7
= 32 + 30
= 62
k cho mk nha
a, 26 + 17 + 23 + 14
= ( 26 + 14 ) + ( 17 + 23 )
= 40 + 40
= 80
b, 46 + 82 + 18 + 54
= ( 46 + 54 ) + ( 82 + 18 )
= 100 + 100
= 200
c, 37 - 5 + 37 - 7
= 32 + 30
= 62
a.80 b.200 c.62
a 26 + 17 + 23 + 14
= ( 26 + 14) +(17+23)
=40+40=80
b 46+82 +18+54
= (46 +54)+(82+18)
=100 +100=200
c 37-5+37 -7
= (7-5)+(37-37)
= 2+ 0=2
chúc bạn hok tốt