-25.72+25.21-49.25 b,35[14-23]-23[14-35] c, 8154-[674+8154]+[-98+674]
1. -25.72+25.21-49.25
2. 35( 14 - 23) - 23 (14 - 35)
3. 8154 - (674 + 8154) + (-98 + 674)
4. 25.21 + 25.72 + 49.25
5. 27(13 - 16) - 16(13 - 27)
6. -1911 - (1234 - 1911)
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
Tính hợp lí nhất
1.2155- (174 + 2155) + (-68 + 174)-25.72 + 25.21 - 49.2535.(14 - 23) - 23.(14-358154 - (674 + 8154) + (-98 + 674)-25.21 + 25.72 + 49.2527.(19-16) - 16.(13 - 27)\(a,1.2155-\left(174+2155\right)+\left(-68+174\right)\)
\(=2155-2155-174+174-68\)
\(=-68\)
\(b,-25.72+25.21-49.25\)
\(=25\left(-72+25-49\right)\)
\(=25.\left(-96\right)\)
\(=-2400\)
tính hợp lí
1. 2155-(174+2155)+(-68+174)
2. -25.72+25.21-49.25
3. 35.(14-23)-23.(14-35_
4.8154-(674+8154)+(-98+674)
Tính hợp lí nhất :
1/2155-(174+2155)+(-68+174)
2/-25.72+25.21-49.25
3/35(14-23)-23(14-35)
4/8154-(674+8154)+(-98+674)
5/-25.21+25.72+49.25
6/27(13-16)-16(13-27)
7/-1911-(1234-1911)
8/156.72+28.156
9/32.(-39)+16.(-22)
10/-1945-_567-1945
11/184.33+67.184
a2/44.(-36)+22.(-28)
tính hợp lí:
35.(14-23)-23.(14-35)
8154-(674+8154)+(-98+674)
27.(13-16)-16.(13-27)
a, 35.(14-23)-23.(14-35) = 35.14-35.23-23.14-23.35 =14.(35-23) -35.23 - 23.35 = 14.12 = 168
bn nào vừa **** cho mih vậy. thanks nha.!^_^
b, 8154-(674+8154)+(-98+674)
=8154-674-8154-98+674
=(8154-8154)+(-674+674)-98
=0+0-98
=-98
Tính hợp lí nhất
1, 2155– (174 + 2155) + (-68 + 174) 2, -25 . 72 + 25 . 21 – 49 . 25 3, 35(14 –23) – 23(14–35) 4, 8154– (674 + 8154) + (–98 + 674) 5, – 25 . 21 + 25 . 72 + 49 . 25 6, 27(13 – 16) – 16(13 – 27)
|
7, –1911 – (1234 – 1911) 8, 156.72 + 28.156 9, 32.( -39) + 16.( –22) 10, –1945 – ( 567– 1945) 11, 184.33 + 67.184 12, 44.( –36) + 22.( –28)
|
1) \( 2155 – (174 + 2155) + (-68 + 174) = -68\) 2) \(-25 . 72 + 25 . 21 – 49 . 25=-2500\) 3) \(35.(14 –23) – 23.(14–35)=168\) 4) \(8154 – (674 + 8154) + (–98 + 674)=-98\) 5) \(25.21+25.72+49.25=2399\) 6) \(27.(13-16)-16.(13-27)=143\) 7) \(–1911 – (1234 – 1911) =-1234\) |
Bài 6. Tính giá trị biểu thức bằng cách hợp lí nhất nếu có thể:
1, 2155– (174 + 2155) + (-68 + 174) 2, -25 . 72 + 25 . 21 – 49 . 25 3, 35(14 –23) – 23(14–35) 4, 8154– (674 + 8154) + (–98 + 674) 5, – 25 . 21 + 25 . 72 + 49 . 25 6, 27(13 – 16) – 16(13 – 27) | 7, –1911 – (1234 – 1911) 8, 156.72 + 28.156 9, 32.( -39) + 16.( –22) 10, –1945 – ( 567– 1945) 11, 184.33 + 67.184 12, 44.( –36) + 22.( –28) |
8: =156x200=31200
10: =-1945-567+1945=-567
Tính hợp lí nhất:
1) 2155 - (174 + 2155) + (-68 + 174)
2) -25 . 72 + 25 . 21 - 49 . 25
3) 35(14 - 23) - 23(14 - 35)
4) 8154 - (674 + 8154) + (-98 + 674)
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.(-9)-23.(-21)
=(-315)-(-483)
=168
4) 8154 - (674 + 8154) + (-98 + 674)
= 8154-674-8154-98+674
=(8154-8154) + (-674+674) - 98
=0+0-98
=-98
Tính hợp lí nhất
1. 2155- (174 + 2155) + (-68 + 174)
2. -25 * 72 + 25 * 21 - 49 * 25
3. 35* (14-23) - 23 * (14-35)
4. 8154 - (674 + 8154) + (-98 + 674)
5. -25 * 21 + 25 * 72 + 49 * 25
6. 27* (13 - 16) - 16* (13 - 27)
7.-1911 - ( 1234 - 1911)
8.156 * 72 + 28 *156
9. 32 * (-39) + 16 * (-22)
10. -1945 - ( 567 - 1945 )
11. 184 * 33 + 67 * 184
12. 44 * ( -36 ) + 22 * ( -28)
Mọi người giúp em với
1: Ta có: \(2155-\left(174+2155\right)+\left(-68+174\right)\)
\(=2155-174-2155-68+174\)
=-68
2) Ta có: \(-25\cdot72+25\cdot21-49\cdot25\)
\(=-25\cdot\left(72-21+49\right)\)
\(=-25\cdot100=-2500\)