80400-(4300+870÷ 15) 240×78÷( 154- 1 15)

1437×27+27×563 〔75-( 12+ 18)〕÷ 15

2 160÷〔(83-79)× 18〕 280+840÷24×5

325÷ 13×(266-250) 85×(95- 1440÷24)

58870÷( 105+20×2) 1437×27+27×563

8 1432÷( 13×52+78) [37.85-(7.85+6.4)] ×30

156×[( 17.7-7.2)÷3] (947-599)+76×64

36×(9 13-276÷23) [ 192-(54+38)]×67

[(7. 1-5.6)×0.9- 1. 15]÷2.5 8 1432÷( 13×52+78)

5.4÷[2.6×(3.7-2.9)+0.62] (947-599)+76×64 60-(9.5+28.9)]÷0. 18 2.88 1÷0.43-0.24×3.5 20×[(2.44- 1.8)÷0.4+0. 15] 28-(3.4 / kloc-0/.25×2.4) 0.8×〔 15.5-(3.2 1 5.79)〕 (3 1.8 3.2×4)÷5 194-64.8÷ 1.8×0.9 36.72÷4.25×9.9 3.4 16÷(0.0 16×35) 0.8×[( 10-6.76)÷ 1.2]

( 136+64)×(65-345÷23) (6.8-6.8×0.55)÷8.5

0. 12× 4.8÷0. 12×4.8 (58+37)÷(64-9×5)

8 12-700÷(9+3 1× 1 1) (3.2× 1.5+2.5)÷ 1.6

85+ 14×( 14+208÷26) 120-36×4÷ 18+35

(284+ 16)×(5 12-8208÷ 18) 9.72× 1.6- 18.305÷7

4/7÷[ 1/3×(3/5-3/ 10)] (4/5+ 1/4)÷7/3+7/ 10

12.78-0÷( 13.4+ 156.6 ) 37.8 12-700÷(9+3 1× 1 1) ( 136+64)×(65-345÷23) 3.2×( 1.5+2.5)÷ 1.6

85+ 14×( 14+208÷26) (58+37)÷(64-9×5)

(6.8-6.8×0.55)÷8.5 (284+ 16)×(5 12-8208÷ 18)

0. 12× 4.8÷0. 12×4.8 (3.2× 1.5+2.5)÷ 1.6

120-36×4÷ 18+35 10. 15- 10.75×0.4-5.7

5.8×(3.87-0. 13)+4.2×3.74 347+45×2-4 160÷52

32.52-(6+9.728÷3.2)×2.5 87(58+37)÷(64-9×5)

[(7. 1-5.6)×0.9- 1. 15] ÷2.5 (3.2× 1.5+2.5)÷ 1.6

5.4÷[2.6×(3.7-2.9)+0.62] 12×6÷( 12-7.2)-6

3.2×6+( 1.5+2.5)÷ 1.6 (3.2× 1.5+2.5)÷ 1.6

5.8×(3.87-0. 13)+4.2×3.74

33.02-( 148.4-90.85)÷2.5

Respondent: 75479 155 1- magic apprentice level 1 10-5 13:26.

(1) Calculation problem:

( 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)

(9)(- 17/4)+(- 10/3)+(+ 13/3)+( 1 1/3)

( 10)(- 1.8)+(+0.2)+(- 1.7)+(0. 1)+(+ 1.8)+(+ 1.4)

( 1 1)(+ 1.3)-(+ 17/7)

( 12)(-2)-(+2/3)

( 13)|(-7.2)-(-6.3)+( 1. 1)|

( 14)|(-5/4)-(-3/4)|-| 1-5/4-|-3/4|)

( 15)(-2/ 199)*(-7/6-3/2+8/3)

( 16)4a)*(-3b)*(5c)* 1/6

There are still 50 questions, but there are no answers.

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

1 1.7 × 5/49 + 3/ 14

12.6 ×( 1/2 + 2/3 )

13.8 × 4/5 + 8 × 1 1/5

14.3 1 × 5/6 – 5/6

15.9/7 - ( 2/7 – 10/2 1 )

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

2 1.5/7 × 3/25 + 3/7

22.3/ 14 ×× 2/3 + 1/6

23. 1/5 × 2/3 + 5/6

24.9/22 + 1/ 1 1 ÷ 1/2

25.5/3 × 1 1/5 + 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 × 2 1/ 16 + 1/2

30. 10 1 × 1/5 – 1/5 × 2 1

3 1.50+ 160÷40 (58+370)÷(64-45)

32. 120- 144÷ 18+35

33.347+45×2-4 160÷52

34(58+37)÷(64-9×5)

35.95÷(64-45)

36. 178- 145÷5×6+42 420+580-64×2 1÷28

37.8 12-700÷(9+3 1× 1 1) ( 136+64)×(65-345÷23)

38.85+ 14×( 14+208÷26)

39.(284+ 16)×(5 12-8208÷ 18)

40. 120-36×4÷ 18+35

4 1.(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

5 1.-5+58+ 13+90+78-(-56)+50

52.-7*2-57/(3

53.(-7)*2/( 1/3)+79/(3+6/4)

54. 123+456+789+98/(-4)

55.369/33-(-54-3 1/ 15.5)

56.39+{3x[42/2x(3x8)]}

57.9x8x7/5x(4+6)

58. 1 1x 22/(4+ 12/2)

59.94+(-60)/ 10

1.

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)

(2) Fill in the blanks:

(1) zero minus the inverse of a, the result is _ _ _ _ _ _ _ _; ② if a-b >; A, then B is _ _ _ _ _ _ _ _ _ _ _; (3) subtract-π from -3. 14, and the difference should be _ _ _ _ _ _ _ _; (4) The minuend is-12(4/5), with a difference of 4.2, so the minuend should be _ _ _ _ _ _ _ _ _ _ _ _; (5) If B-A

(3) True or false:

(1) When a number subtracts a negative number, the difference is less than the minuend. (2) When a number subtracts a positive number, the difference is less than the minuend. (3) Subtract any number from 0, and the difference is always equal to the reciprocal of this number. (4) If X+(-Y)=Z, then X=Y+Z (5) If 0, b|b|, then a-b >; 0

1) Multiple choice questions:

(1) It is known that A and B are two rational numbers. If their quotient a/b=0, then () (A)a=0 and b≠0 (B)a=0 (C)a=0 or b=0 (D)a=0 or b≠0. -1 and-1; 0 and 0; -2/3 and -3/2, where the reciprocal is () (a) only (b) only (c) only (d) both are (3) If a/|b|(b≠0) is a positive integer, then () |b| is the divisor of a (. B, then there must be () (a) A)A+b & gt；; a(B)a-B & gt； a(C)2a & gt； ab(D)a/b & gt； 1

(2) Fill in the blanks:

(1) When |a|/a= 1, a _ _ _ _ _ _ 0; When |a|/a=- 1, a _ _ _ _ _ _ 0; (fill in > 0, then a _ _ _ _ _ _ 0; (1 1) If ab/c0, then B _ _ _ _ _ _ 0; (12) if a/b >; 0，b/c(-0.3)4 & gt； - 106(B)(-0.3)4 >； - 106 >(-0.2)3(C)- 106 & gt； (-0.2)3 & gt； (-0.3)4(D)(-0.3)4 & gt； (-0.2)3 & gt； -106 (4) If A is a rational number and A2 >；; A, then the value range of A is () (a) A.

(2) Fill in the blanks:

(1)23, 3 is _ _ _ _ _, 2 is _ _ _ _ _ _, and the power is _ _ _ _ _ _ _ _; If 3 is regarded as a power, its cardinal number is _ _ _ _ _ _ _ _,

The index is _ _ _ _ _ _ _ _; (2) According to the meaning of power: (-2)3 stands for _ _ _ _ _ _ _ multiplication; (-3)2v represents _ _ _ _ _ multiplication; -23 means _ _ _ _ _. (3) The rational number whose square equals 36/49 is _ _ _ _ _ _ _; The cubic number equal to -27/64 is _ _ _ _ _ _ _ (4) Write a positive number greater than 10 as a* 10n (n is a positive integer), where the range of a is _ _ _ _ _ _ _ _, where n is an integer.

The number of digits is less than _ _ _ _ _ _, which is called scientific notation; (5) Write down the following numbers by scientific notation: 4000 = _ _ _ _ _ _ _ _ _ _ _ _; 950000=________________; earth

The mass is about 49800 ... 0g (28 bits), which can be recorded as _ _ _ _ _ _ _ _; (6) What are the numbers recorded by scientific notation, namely105 = _ _ _ _ _ _ _ _ _ _ _; 2* 105=______________; 9.7 *107 = _ _ _ _ _ _ 9.756 *103 = _ _ _ _ _ (7) The following numbers are natural numbers. 7* 106 is 3.78* 107 is _ _ _ _ digits; 10 10 is _ _ _ _ _ digits; (8) If rational number m 0, B0 (b) a-| b | > 0 (c) A2+B3 > 0 (d) A <; 0 (6) The minimum value of algebraic expression (a+2)2+5 is () (a) A = 0 (b) A = 2 (c) A =-2 (d) A0 (b) B-A >; 0 (c) A and B are reciprocal; (D)-ab (C)a

(5) The approximate value 1.20 obtained by rounding method represents the range of the exact number a ().

(A) 1. 195≤A & lt； 1.205(B) 1. 15≤a & lt； 1. 18(C) 1. 10≤a & lt； 1.30(D) 1.200≤a & lt； 1.205 (6) The following statements are correct: (a) The accuracy of similarity number 3.80 is the same as that of similarity number 38; (b) The number of significant digits of similarity number 38.0 is the same as that of similarity number 38. (c)3. 14 16 has three significant digits 3, 1 4 after being accurate to the percentile; (d) Write 123* 102 as 1.23* 104 with four significant digits.

(2) Fill in the blanks:

(1) Write the precision and significant figures of the following rounded approximations: (1) Approximate number 85 is accurate to _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ (3) The divisor of 5.2 million is accurate to _ _ _ _ _ _ _ _, and the effective number is _ _ _ _ _ _ _ _; (4) The approximate value of 0.20 is accurate to _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

The divisor 2.7 183 is accurate to _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(3) True or false:

(1) The approximate value of 25.0 is exactly a dash, and the significant digits are 2,5; (2) Similarity number 4000 is as accurate as similarity number 4000; (3) The divisor 4000 is as accurate as the divisor 4 * 10 3; (4) The approximate value of 9.949 accurate to 0.0 1 is 9.95.

Exercise 8 (Level B)

(1) Use rounding method to approximate the following figures (three significant figures are required): (1) 37.27 (2) 810.9 (3) 0.0045078 (4) 3.079.

(2) Use rounding method to approximate the following numbers (accurate to thousands): (1) 37890.6 (2) 213612.4 (3)1906.57.

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

I wish you progress in your study! My hands are sore.