1. Can you fill it out quickly and accurately? (20×2 points = 40 points)
1. If 5m moving eastward is marked as +5m, 3m moving westward should be marked as m. ..
2. The number that is neither positive nor negative is.
3. The inverse of-(-3) is; The reciprocal of 1 is.
4. If a < 0, |a|=.
5. The coefficient of single item-is, and the number is.
6. If | A+3 |+(b-2) 2 = 0, then A-B =.
7. as shown in figure 1: ab.
The complementary angle of 8.69 30' is equal to.
9.0.02079 Keep three significant figures.
10. The sum of monomial -x2my and x6yn is monomial, then m =, n =.
1 1. Polynomials a4+4a3b-6ab2+4ab3 are arranged in descending order of B as follows.
12. Fix a piece of wood on the wall, at least nail it.
According to.
13. Write 15800000 according to scientific notation.
14. As shown in Figure 2: ∠ 1 = ∠ 2, then ∠, ∠ bad+= 180.
Second, you can definitely choose the right one! (2 points× 8 =16 points)
15. Regarding rational numbers, the following statement is true ().
(a) the largest number; (b) has the smallest absolute quantity.
(c) The minimum number; (d) Has the largest absolute quantity.
16. It is known that A, B and C are rational numbers, so the inverse of a+b+c is ().
(A)b+ A-C(B)-B- A-C(C)-B- A+C(D)B- A+C
17. There are any three points on the plane, after which the number of straight lines can be drawn ()
(A) 1 (B) 3 (C) 1 or 3 (D) countless articles.
18.a and b are reciprocal, and x and y are reciprocal, so the value of (A+B) (X+Y)-AB is ().
(a) 0 (b) 1 (c)- 1 (d) cannot be determined.
19. Among the following groups, the group that correctly judges the size relationship is ().
(A)(-2)3 >； -23(B)(-2)2 & lt； 22
(C) ->- (D)(-2)3>(-2)2
20. If the single digit of a two-digit number is A and the ten-digit number is B, then this two-digit number can be expressed as ().
(A)A+B(B)ba(C) 10b+A(D) 10a+B
2 1. The cube shown in the figure, if expanded, can be () in the figure below.
(A) (B) (C) (D)
22. In the drawing, ∠ 1 and ∠2 are at the same angle ().
(A)①、② (B)①、③ (C)②、③ (D)②、④
① ② ③ ④
Third, do the math! Do not make mistakes! ! !
23. Calculation: (3 points for each question, *** 12 points)
( 1) (2)- 14+50÷22×(― )
(3) (4)0÷(-5)- 53- 5
24. Simplified evaluation: (2x-xyz)- 2(x-y+xyz)+(xyz-2y),
Where x = 1, y = 2 and z =-3; ; (5 points)
Fourth, know the map calculation: be sure to look! ! ! (3 points for each question, ***6 points)
25. As shown in the figure, given that the line segment AB = 10㎝, and C is the midpoint of AB, find the length of AC;
26. as shown in the figure, it is known that: AD//BC, 1 = C, B = 60, and the degree: c;
Verb (abbreviation of verb) explanation: (***5 points)
27. It is known that B, A and E are on a straight line, 1 = B Q: Is C equal to 2? Why?
Sixth, inquiry questions: have a look, don't be confused! ! !
28.(5 points) Observe the graph and answer this question: If AD//BC is used, what conditions should be added?
(Requirements: Find at least 5 conditions)
Answer: ① ②
③ ④
⑤
29.(5 points) There is such a question: "Calculate (2x-3x y-2xy )-(x-2xy+y )+(- x".
+3x y-y), where x =, y =- 1. "A classmate mistakenly copied" x = "as" x =- ",but his calculation result is also correct. Try to explain why? And find this result?
30.(6 points) People's heart rate during exercise is usually related to age. Use a to indicate a person's age, and b.
Represents the maximum number of heartbeats per minute that this person can bear during normal exercise, then b = 0.8 (220–a).
(1) Under normal circumstances, what is the maximum number of heartbeats a teenager of 14 can bear during exercise?
(2) When a 45-year-old man is exercising, his heart beats 22 times at the speed of 10 second. Is he in danger? Why?
Seven, plus questions (each question 10, 20 points * * *)
3 1, if | ab-2 |+(b- 1)= 0.
(1) Find the values of a and b.
(2) Find the value of b+(- b)
(3) Find the value of++...+
32. It is known that AB//DE, AC//DF,
(1) Description: ∠ A = ∠ D;
(2) Write the above conclusions in words in the form of "two straight lines are parallel and the same angle is equal";
(3) Is there any other relationship between ∠A and ∠D under this condition? If you think there is, write it out;