初二下冊數學計算題及答案,八年級下冊數學計算題及答案100道

時間 2021-05-05 14:00:38

1樓:匿名使用者

①5√8-2√32+√50

=5*3√2-2*4√2+5√2

=√2(15-8+5)

=12√2

②√6-√3/2-√2/3

=√6-√6/2-√6/3

=√6/6

③(√45+√27)-(√4/3+√125)=(3√5+3√3)-(2√3/3+5√5)=-2√5+7√5/3

④(√4a-√50b)-2(√b/2+√9a)=(2√a-5√2b)-2(√2b/2+3√a)=-4√a-6√2b

⑤√4x*(√3x/2-√x/6)

=2√x(√6x/2-√6x/6)

=2√x*(√6x/3)

=2/3*|x|*√6

⑥(x√y-y√x)÷√xy

=x√y÷√xy-y√x÷√xy

=√x-√y

⑦(3√7+2√3)(2√3-3√7)

=(2√3)^2-(3√7)^2

=12-63

=-51

⑧(√32-3√3)(4√2+√27)

=(4√2-3√3)(4√2+3√3)

=(4√2)^2-(3√3)^2

=32-27

=5 ⑨(3√6-√4)?

=(3√6)^2-2*3√6*√4+(√4)^2=54-12√6+4

=58-12√6

⑩(1+√2-√3)(1-√2+√3)

=[1+(√2-√3)][1-(√2-√3)]=1-(√2-√3)^2

=1-(2+3+2√6)

=-4-2√6

(1)5√12×√18

=5*2√3*3√2

=30√6

2樓:紫色極端

你不說哪道題或者具體哪本書沒有辦法回答啊

八年級下冊數學計算題及答案100道

3樓:冥冥自有公論

①5√8-2√32+√50 =5*3√2-2*4√2+5√2 =√2(15-8+5) =12√2 ②√6-√3/2-√2/3 =√6-√6/2-√6/3 =√6/6 ③(√45+√27)-(√4/3+√125) =(3√5+3√3)-(2√3/3+5√5) =-2√5+7√5/3 ④(√4a-√50b)-2(√b/2+√9a) =(2√a-5√2b)-2(√2b/2+3√a) =-4√a-6√2b ⑤√4x*(√3x/2-√x/6) =2√x(√6x/2-√6x/6) =2√x*(√6x/3) =2/3*|x|*√6 ⑥(x√y-y√x)÷√xy =x√y÷√xy-y√x÷√xy =√x-√y ⑦(3√7+2√3)(2√3-3√7) =(2√3)^2-(3√7)^2 =12-63 =-51 ⑧(√32-3√3)(4√2+√27) =(4√2-3√3)(4√2+3√3) =(4√2)^2-(3√3)^2 =32-27 =5 ⑨(3√6-√4)? =(3√6)^2-2*3√6*√4+(√4)^2 =54-12√6+4 =58-12√6 ⑩(1+√2-√3)(1-√2+√3) =[1+(√2-√3)][1-(√2-√3)] =1-(√2-√3)^2 =1-(2+3+2√6) =-4-2√6 (1)5√12×√18 =5*2√3*3√2 =30√6; (2)-6√45×(-4√48) =6*3√5*4*4√3 =288√15; (3)√(12a)×√(3a) /4 =√(36a^2)/4 =6a/4 =3a/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) 9. 9x^2(x-1)^2-3(x^2-x)-56 =9x^2(x-1)^2-3x(x-1)-56 =[3x(x-1)-8][3x(x-1)+7] =(3x^2-3x-8)(3x^2-3x+7) 有理數練習 練習一(b級) (一)計算題: (1)23+(-73) (2)(-84)+(-49) (3)7+(-2.

04) (4)4.23+(-7.57) (5)(-7/3)+(-7/6) (6)9/4+(-3/2) (7)3.

75+(2.25)+5/4 (8)-3.75+(+5/4)+(-1.

5) 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) 9. 9x^2(x-1)^2-3(x^2-x)-56 =9x^2(x-1)^2-3x(x-1)-56 =[3x(x-1)-8][3x(x-1)+7] =(3x^2-3x-8)(3x^2-3x+7) 1.

125*3+125*5+25*3+25 2.9999*3+101*11*(101-92) 3.(23/4-3/4)*(3*6+2) 4.

3/7 × 49/9 - 4/3 5. 8/9 × 15/36 + 1/27 6. 12× 5/6 – 2/9 ×3 7.

8× 5/4 + 1/4 8. 6÷ 3/8 – 3/8 ÷6 9. 4/7 × 5/9 + 3/7 × 5/9 10.

5/2 -( 3/2 + 4/5 ) 11. 7/8 + ( 1/8 + 1/9 ) 12. 9 × 5/6 + 5/6 13.

3/4 × 8/9 - 1/3 14. 7 × 5/49 + 3/14 15. 6 ×( 1/2 + 2/3 ) 16.

8 × 4/5 + 8 × 11/5 17. 31 × 5/6 – 5/6 18. 9/7 - ( 2/7 – 10/21 ) 19.

5/9 × 18 – 14 × 2/7 20. 4/5 × 25/16 + 2/3 × 3/4 21. 14 × 8/7 – 5/6 × 12/15 22.

17/32 – 3/4 × 9/24 23. 3 × 2/9 + 1/3 24. 5/7 × 3/25 + 3/7 25.

3/14 ×× 2/3 + 1/6 26. 1/5 × 2/3 + 5/6 27. 9/22 + 1/11 ÷ 1/2 28.

5/3 × 11/5 + 4/3 29. 45 × 2/3 + 1/3 × 15 30. 7/19 + 12/19 × 5/6 31.

1/4 + 3/4 ÷ 2/3 32. 8/7 × 21/16 + 1/2 33. 101 × 1/5 – 1/5 × 21 34.

50+160÷40 35.120-144÷18+35 36.347+45×2-4160÷52 37(58+37)÷(64-9×5) 38.

95÷(64-45) 39.178-145÷5×6+42 40.812-700÷(9+31×11) 41.

85+14×(14+208÷26) 43.120-36×4÷18+35 44.(58+37)÷(64-9×5) 45.

(6.8-6.8×0.

55)÷8.5 46.0.

12× 4.8÷0.12×4.

8 47.(3.2×1.

5+2.5)÷1.6 48.

6-1.6÷4= 5.38+7.

85-5.37= 49.7.

2÷0.8-1.2×5= 6-1.

19×3-0.43= 50.6.

5×(4.8-1.2×4)= 51.

5.8×(3.87-0.

13)+4.2×3.74 52.

32.52-(6+9.728÷3.

2)×2.5 53.[(7.

1-5.6)×0.9-1.

15] ÷2.5 54.5.

4÷[2.6×(3.7-2.

9)+0.62] 55.12×6÷(12-7.

2)-6 56.12×6÷7.2-6 57.

0.68×1.9+0.

32×1.9 58.58+370)÷(64-45) 59.

420+580-64×21÷28 60.136+6×(65-345÷23) 15-10.75×0.

4-5.7 62.18.

1+(3-0.299÷0.23)×1 63.

(6.8-6.8×0.

55)÷8.5 64.0.

12× 4.8÷0.12×4.

8 65.(3.2×1.

5+2.5)÷1.6 66.

3.2×6+(1.5+2.

5)÷1.6 67.0.

68×1.9+0.32×1.

9 68.10.15-10.

75×0.4-5.7 69.

5.8×(3.87-0.

13)+4.2×3.74 70.

32.52-(6+9.728÷3.

2)×2.5 71.[(7.

1-5.6)×0.9-1.

15] ÷2.5 72.5.

4÷[2.6×(3.7-2.

9)+0.62] 73.12×6÷(12-7.

2)-6 74.12×6÷7.2-6 75.

33.02-(148.4-90.

85)÷2.5 1) 76.(25%-695%-12%)*36 77.

/4*3/5+3/4*2/5 78.1-1/4+8/9/7/9 79.+1/6/3/24+2/21 80.

/15*3/5 81.3/4/9/10-1/6 82./3+1/2)/5/6-1/3]/1/7 83.

/5+3/5/2+3/4 84.(2-2/3/1/2)]*2/5 85.+5268.

32-2569 86.3+456-52*8 87.5%+6325 88.

/2+1/3+1/4 2) 89+456-78 3) 5%+. 3/7 × 49/9 - 4/3 4) 9 × 15/36 + 1/27 5) 2× 5/6 – 2/9 ×3 6) 3× 5/4 + 1/4 7) 94÷ 3/8 – 3/8 ÷6 8) 95/7 × 5/9 + 3/7 × 5/9 9) 6/2 -( 3/2 + 4/5 ) 10) 8 + ( 1/8 + 1/9 ) 11) 8 × 5/6 + 5/6 12) 1/4 × 8/9 - 1/3 13) 10 × 5/49 + 3/14 14) 1.5 ×( 1/2 + 2/3 ) 15) 2/9 × 4/5 + 8 × 11/5 16) 3.

1 × 5/6 – 5/6 17) 4/7 - ( 2/7 – 10/21 ) 18) 19 × 18 – 14 × 2/7 19) 5 × 25/16 + 2/3 × 3/4 20) 4 × 8/7 – 5/6 × 12/15 21) 7/32 – 3/4 × 9/24 22) 1、 2/3÷1/2-1/4×2/5 2、 2-6/13÷9/26-2/3 3、 2/9+1/2÷4/5+3/8 4、 10÷5/9+1/6×4 5、 1/2×2/5+9/10÷9/20 6、 5/9×3/10+2/7÷2/5 7、 1/2+1/4×4/5-1/8 8、 3/4×5/7×4/3-1/2 9、 23-8/9×1/27÷1/27 10、 8×5/6+2/5÷4 11、 1/2+3/4×5/12×4/5 12、 8/9×3/4-3/8÷3/4 13、 5/8÷5/4+3/23÷9/11 23) 1.2×2.5+0.

8×2.5 24) 8.9×1.

25-0.9×1.25 25) 12.

5×7.4×0.8 26) 9.

9×6.4-(2.5+0.

24)(27) 6.5×9.5+6.

5×0.5 0.35×1.

6+0.35×3.4 0.

25×8.6×4 6.72-3.

28-1.72 0.45+6.

37+4.55 5.4+6.

9×3-(25-2.5)2×41846-620-380 4.8×46+4.

8×54 0.8+0.8×2.

5 1.25×3.6×8×2.

5-12.5×2.4 28×12.

5-12.5×20 23.65-(3.

07+3.65) (4+0.4×0.

25)8×7×1.25 1.65×99+1.

65 27.85-(7.85+3.

4) 48×1.25+50×1.25×0.

2×8 7.8×9.9+0.

78 (1010+309+4+681+6)×12 3×9146×782×6×854 5.15×7/8+6.1-0.

60625 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 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 51.[(7.

1-5.6)×0.9-1.

15] ÷2.5 52.5.

4÷[2.6×(3.7-2.

9)+0.62] 53.12×6÷(12-7.

2)-6 (4)12×6÷7.2-6 102×4.5 7.

8×6.9+2.2×6.

9 5.6×0.25 8×(20-1.

25) 1)127+352+73+44 (2)89+276+135+33 (1)25+71+75+29 +88 (2)243+89+111+57 9405-2940÷28×21 920-1680÷40÷7 690+47×52-398 148+3328÷64-75 360×24÷32+730 2100-94+48×54 51+(2304-2042)×23 4215+(4361-716)÷81 (247+18)×27÷25 36-720÷(360÷18) 1080÷(63-54)×80 (528+912)×5-6178 8528÷41×38-904 264+318-8280÷69 (174+209)×26- 9000 814-(278+322)÷15 1406+735×9÷45 3168-7828÷38+504 796-5040÷(630÷7) 285+(3000-372)÷36 1+5/6-19/12 3x(-9)+7x(-9 (-54)x1/6x(-1/3) 1.18.1+(3-0.

299÷0.23)×1 2.(6.

8-6.8×0.55)÷8.

5 3.0.12× 4.

8÷0.12×4.8 4.

(3.2×1.5+2.

5)÷1.6 (2)3.2×(1.

5+2.5)÷1.6 5.

6-1.6÷4= 5.38+7.

85-5.37= 6.7.

2÷0.8-1.2×5= 6-1.

19×3-0.43= 7.6.

5×(4.8-1.2×4)= 0.

68×1.9+0.32×1.

9 8.10.15-10.

75×0.4-5.7 9.

5.8×(3.87-0.

13)+4.2×3.74 10.

32.52-(6+9.728÷3.

2)×2.5 11.[(7.

1-5.6)×0.9-1.

15] ÷2.5 12.5.

4÷[2.6×(3.7-2.

9)+0.62] 13.12×6÷(12-7.

2)-6 14.12×6÷7.2-6 15.

33.02-(148.4-90.

85)÷2.5 7×(5/21+9/714) 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) 寫完一遍後再別這些題寫一遍,以此類推,老師們看作業都是一看而過不會一個一個批的。

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