Bài 1:
1) 12.18 + 14.3 - 255:17
=216+42-15
=258-15
=243
2) 68 +42.5-625:25
=68+210-25
=278-25
=253
3) 13+ 21.5 - (198:11-8)
=13+ 105 - (18-8)
=13+105-10
=118-10
=108
4) 272:16-5+4.(30-5-255:17)
=17-5+4.(30-5-15)
=17-5+4.(25-15)
=17-5+4.10
=17-5+40
=12+40
=52
5) 25.8 -12.5 +272:17-8
=200-60+16-8
=140+16-8
=156-8
=148
6) 125:25+14-142:71
=5 + 14 - 2
=19-2
=17
7) 13.17 - 256:16+14:7-1
=221-16+2-1
=205+2-1
=207-1
=206
8) 15.24- 14.5 .(145:5-27)
=360-70.(29-27)
=360-70.2
=360-140
=220
9) 289:17- 324:18+18:3
=17-18+6
= (-1) + 6
=5
10) 18.3 - 182+3.(51:17)
=54-185.3
=54-555
=-501
11) (64+115+36)-25.8
=(179+36)-200
=215-200
=200
12) 15.8-(17-30+83)-144:6
=120-(-13+83)-24
=120-70-24
=50-24
=26
13) 19+19.99-25.8
=19+1881-200
=1900-200
=1700
14) 250:50- (46-75+54):5
=5-(-29+54):5
=5-(-5):5
=5-(-1)
=6
15) 13. (17-95+83):5-18:9
=13.(-78+83):5-162
=13.5:5-162
=65:5-162
=13-162
=-149
16) 140-180.(47-90+43)+7
=140-180.(-43+43)+7
=140-180.0+7
=140-0+7
=140+7
=147
17) 24.(15+30+85-120):10
=24.(45+85+120):10
=24.(130-120):10
=24. 10:10
=240:10
=24
18) 27+73- 30:(25-10)
=27+73-30:15
=27+73-2
=100-2
=98
19) 18-4.(27-90+73):10
=18-4.(-63+73):10
=18-4.10:10
=18-40:10
=(-22):10
=-2,2
20) 16-25.8:(100.2)
=16-200:200
=16-1
=15
Bài 2 :
1, 13 . 58 . 4 + 32 . 26 . 2 + 52 . 10
= 52 . 58 + 32 . 52 + 52 . 10
= 52 . 100
= 5200
2, 15 . 37 . 4 + 120 . 21 + 21 . 5 . 12
= 60 . 37 + 2 . 60 . 21 + 21 . 60
= 60 . 37 + 60 . 42 + 60 . 21
= 60 . 100
= 6000
3, 14 . 35 . 5 + 10 . 25 . 7 + 20 . 70
= 70 . 35 + 70 . 25 + 70 . 20
= 70 . 80
= 5600
4, 15 ( 27 + 18 + 6 ) + 15 ( 23 + 12 )
= 15 . 51 + 15 . 35
= 15 . 86
= ( tự tính nhoa 😗😗😗 )
5, 24 ( 15 + 49 ) + 12 ( 50 + 42 )
= 24 . 64 + 12 . 94
= 24 . 64 + 12 . 2 . 47
= 24 . 111
= ( tự tính nhoa 😗😗😗 )
Cho mk ctrlhn nhó . . . mãi yew ❤❤❤
