a) 27(13-16) -16(13-27)

= 27.(-3)       -16.(-14)

= (-81)          -(-224)

= -81             + 244

= 143

b) -25.21+25.72+49.25

= -525  + 1800+ 1225

= 1275  + 1225

= 2500

c) -1911-(1234-1911)

= -1991 - (-677)

= -1991 + 677

= -1234

d) -1945-(567-1945)

= -1945 - (-1378)

= -1945 + 1378

= 567

1. -25.72 + 25.21 - 49.25

= 25.(-72) + 25.21 - 49.25

= 25.(-72 + 21 - 49)

= 25. (-100)

= -2500

2. 35(14 - 23) - 23(14 - 35)

= 35. (-9) - 23. (-9)

= -9(35 - 23)

= -9. 12

= -108

3. 8154 -(674 + 8154) + (-98 + 674)

= 8154 - 674 - 8154 + (-98) + 674

= 8154 - 8154 - 674 + 674 + (-98)

= -98

4. 25.21 + 25.72 + 49.25

= 25(21 + 72 + 49)

= 25. 142

= 3550

5. 27(13 - 16) - 16(13 - 27)

= (27.13 - 27.16) - (16.13 - 16.27)

= 27.13 - 27.16 - 16.13 - 16.27

= 27.13 - 16.13 - 27.16 - 16.27

= 27.13 - 16.13

= 13(27 - 16)

= 13.11

= 143

6. -1911 -(1234 - 1911)

= -1911 - 1234 + 1911

= -1911 + 1911 - 1234

= -1234

1,      27.(13-16)-16.(13-27)=27.(-3)-16(-14)=-81-(-224)=143

2       -1911-(1234-1911)=-1911-1234+1911=-1234

3         32.(-39)+16.(-22)=16.2(-39)+16(-22)=16(-78)+16(-22)=16[(-78)+(-22)]=16.(-100)=-1600

4          -(567-1945)-1945=-567+1945-1945=-567

5             44.(-36)+22.(-28)=22.2(-36)+22(-28)=22(-72)+22(-28)=22[(-72)+(-28)]=22.(-100)=-2200

k mình nhé

1: Ta có: \(2155-\left(174+2155\right)+\left(-68+174\right)\)

\(=2155-174-2155-68+174\)

=-68

2) Ta có: \(-25\cdot72+25\cdot21-49\cdot25\)

\(=-25\cdot\left(72-21+49\right)\)

\(=-25\cdot100=-2500\)

1) 2155-(174+2155)+(-68+174)

=2155-174-2155-68+174

=2155-2155+174-174-68

=0+0-68

=-68

2) -25.72+25.21-49.25

=25.[(-72)+21-49]

=25.(-100)

=-2500

3) 35(14 - 23) - 23(14 - 35)

= 35.14 - 35.23 - (23.14 - 23.35)

= 35.14 - 35.23 - 23.14 + 23.35

= (35.14 - 23.14) + (23.55 - 35.23)

= 14.(35-23) + 0

= 14.12 + 0

= 168

4) 8154 - (674 + 8154) + (-98 + 674)

= 8154 - 674 - 8154 - 98 + 674

= (8154 - 8154) + (674 - 674) - 98

= 0 + 0 - 98

= -98

5) (-25).21 + 25.72 + 49.25

= 25.[(-21) + 72 + 49]

= 25.100

= 2500

6) 27(13 - 16) - 16(13 - 27)

= 27.13 - 27.16 - (16.13 - 16.27)

= 27.13 - 27.16 - 16.13 + 16.27

= (27.13 - 16.13) + (16.27 - 27.16)

= 13.(27-16) + 0

= 13.11 + 0

= 143

7) (-1911) - (1234 - 1911)

= (-1911) - 1234 + 1911

= [(-1911) + 1911] - 1234

= 0 - 1234

= -1234

8) 156.72 + 28.156

= 156.(72+28)

= 156.100

= 15600

9) 32.(-39) + 16.(-22)

= 16.2.(-39) + 16.(-22)

= 16.(-78) + 16.(-22)

= 16.[(-78) + (-22)]

= 16.(-100)

= -1600

10) (-1945) - (567 - 1945)

= (-1945) - 567 + 1945

= [(-1945) + 1945] - 567

= 0 - 567

= -567

11) 184.33 + 67.184

= 184.(33 + 67)

= 184.100

= 18400

12) 44.(-36) + 22.(-28)

= 22.2.(-36) + 22.(-28)

= 22.(-72) + 22.(-28)

= 22.[(-72) + (-28)]

= 22.(-100)

= -2200

câu 1 = -68

câu 2 =-2500

câu 3=168

câu 4 =4571

câu 6=124

1) 2155-(174+2155)+(-68+174-7)-1911-(1234-1911)

=2155-174-2155+(-68)+174-7-1911-1234+1911

=(2155-2155)+(174-174)+(1911-1911)-(68+7+1234)

= 0 + 0 + 0 - 1309

= -1309