计算题30道必须要带答案

1个回答

  • 3(20-y)=6y-4(y-11)

    a^3-2b^3+ab(2a-b)

    x^2+y^2)^2-4y(x^2+y^2)+4y^2

    x^2+2x)^2+3(x^2+2x)+x^2+2x+3

    a^3-2b^3+ab(2a-b)

    =a^3+2a^2b-2b^3-ab^2

    =a^2(a+2b)-b^2(2b+a)

    =(a+2b)(a^2-b^2)

    =(a+2b)(a+b)(a-b)

    2.

    (x^2+y^2)^2-4y(x^2+y^2)+4y^2

    =(x^2+y^2-2y)^2

    3.

    (x^2+2x)^2+3(x^2+2x)+x^2+2x+3

    =(x^2+2x)^2+4(x^2+2x)+3

    =(x^2+2x+3)(x^2+2x+1)

    =(x^2+2x+3)(x+1)^2

    4.

    (a+1)(a+2)+(2a+1)(a-2)-12

    =a^2+3a+2+2a^2-3a-2-12

    =3a^2-12

    =3(a+2)(a-2)

    5.

    x^2(y+z)^2-2xy(x-z)(y+z)+y^2(x-z)^2

    =[x(y+z)-y(x-z)]^2

    =(xz+yz)^2

    =z^2(x+y)^2

    6.

    3(a+2)^2+28(a+2)-20

    =[3(a+2)-2][(a+2)+10]

    =(3a+4)(a+12)

    7.

    (a+b)^2-(b-c)^2+a^2-c^2

    =(a+b)^2-c^2+a^2-(b-c)^2

    =(a+b+c)(a+b-c)+(a+b-c)(a-b+c)

    =(a+b-c)(a+b+c+a-b+c)

    =2(a+b-c)(a+c)

    8.

    x(x+1)(x^2+x-1)-2

    =(x^2+x)(x^2+x-1)-2

    =(x^2+x)^2-(x^2+x)-2

    =(x^2+x-2)(x^2+x+1)

    =(x+2)(x-1)(x^2+x+1)

    1. 3/7 × 49/9 - 4/3

    2. 8/9 × 15/36 + 1/27

    3. 12× 5/6 – 2/9 ×3

    4. 8× 5/4 + 1/4

    5. 6÷ 3/8 – 3/8 ÷6

    6. 4/7 × 5/9 + 3/7 × 5/9

    7. 5/2 -( 3/2 + 4/5 )

    8. 7/8 + ( 1/8 + 1/9 )

    9. 9 × 5/6 + 5/6

    10. 3/4 × 8/9 - 1/3

    0.12χ+1.8×0.9=7.2 (9-5χ)×0.3=1.02 6.4χ-χ=28+4.4

    11. 7 × 5/49 + 3/14

    12. 6 ×( 1/2 + 2/3 )

    13. 8 × 4/5 + 8 × 11/5

    14. 31 × 5/6 – 5/6

    15. 9/7 - ( 2/7 – 10/21 )

    16. 5/9 × 18 – 14 × 2/7

    17. 4/5 × 25/16 + 2/3 × 3/4

    18. 14 × 8/7 – 5/6 × 12/15

    19. 17/32 – 3/4 × 9/24

    20. 3 × 2/9 + 1/3

    21. 5/7 × 3/25 + 3/7

    22. 3/14 ×× 2/3 + 1/6

    23. 1/5 × 2/3 + 5/6

    24. 9/22 + 1/11 ÷ 1/2

    25. 5/3 × 11/5 + 4/3

    26. 45 × 2/3 + 1/3 × 15

    27. 7/19 + 12/19 × 5/6

    28. 1/4 + 3/4 ÷ 2/3

    29. 8/7 × 21/16 + 1/2

    30. 101 × 1/5 – 1/5 × 21

    31.50+160÷40 (58+370)÷(64-45)

    32.120-144÷18+35

    33.347+45×2-4160÷52

    34(58+37)÷(64-9×5)

    35.95÷(64-45)

    36.178-145÷5×6+42 420+580-64×21÷28

    37.812-700÷(9+31×11) (136+64)×(65-345÷23)

    38.85+14×(14+208÷26)

    39.(284+16)×(512-8208÷18)

    40.120-36×4÷18+35

    41.(58+37)÷(64-9×5)

    42.(6.8-6.8×0.55)÷8.5

    43.0.12× 4.8÷0.12×4.8

    44.(3.2×1.5+2.5)÷1.6 (2)3.2×(1.5+2.5)÷1.6

    45.6-1.6÷4= 5.38+7.85-5.37=

    46.7.2÷0.8-1.2×5= 6-1.19×3-0.43=

    47.6.5×(4.8-1.2×4)= 0.68×1.9+0.32×1.9

    48.10.15-10.75×0.4-5.7

    49.5.8×(3.87-0.13)+4.2×3.74

    50.32.52-(6+9.728÷3.2)×2.5

    初一下的,Ok?