1. Calculate (-0.25)20 14? The result of (-4)20 15 is ()
A.- 1 B. 1 C.-4 D.4
2. Equation ■x-2y=x+5 is a binary linear equation, and ■ is the coefficient that x is covered by ink. Please infer that the value of ■ belongs to () under the following circumstances.
A. it can't be-1 b can't be -2 c can't be 1 d can't be 2.
3.PM2.5 is a particulate matter with a diameter less than or equal to 0.0000025m at atmospheric pressure, and 0.0000025 is expressed as () by scientific notation.
A.0.25？ 10-5 B.0.25？ 10-6 C.2.5？ 10-5 D.2.5？ 10-6
4. The following calculation is correct ()
A.2a-2= B. -2a2=4a2 C.2a？ 3b=5ab D.3a4？ 2a4=
5. If both x and y in are expanded by 10 times, then the value of this score ().
A. unchanged B. enlarged by 30 times C. enlarged by 10 times D. reduced to its original appearance
6. In order to know the height of students in our school 1200, 200 students were selected for statistical analysis. The following statement is true ().
A. 1200 Students are the whole B. Every student is an individual.
C.200 students are a sample. D. The height of each student is an individual.
7. Simplify: (-)? The result of (x-3) is ()
The second century BC.
8. If the equation -=7 has an increasing root, then the value of k is ().
A.- 1 B.0 C. 1 D.6
9. If the solution of the equation is the same as that of the equation, then the values of a and b are ().
A.B. C. D。
10. As shown in the figure, AD is equally divided? BDF？ 3=? 4. What if? 1=50? ,
? 2= 130? And then what? The degree of CBD is ()
.45 caliber? B.50？
C.60？ D.65？
Second, fill it out carefully (this question is ***8 small questions, with 3 points for each small question and 24 points for * * *).
1 1. Decomposition factor: 3x3-6x2y+3xy2 = _ _ _ _ _ _ _ _ _ _ _ _ _ _.
12. for real numbers a and b, the new operation definition is as follows: a※b=, for example, 2※3=2-3=, calculation [2※(-4)]? [(-4)※(-2)]=___________.
13. Calculation:-22+(-2) 2-(-)-1= _ _ _ _ _ _ _ _ _.
14. If the equation (6a3+3a2)? 6a=(a+ 1)(a+2) holds, then the value of a is _ _ _ _ _ _ _ _.
15. The picture shows the fan-shaped statistical chart of the number of seventh-grade students participating in extracurricular activities (1). If the number of people attending the art class is 16, then the number of people attending other activities is _ _ _ _ _.
/DrawingNo. KLOC-0/5/DrawingNo. KLOC-0/6/DrawingNo. KLOC-0/7
16. As shown in the figure, move the triangular cardboard ABC along the straight line AB to move the point to point B. If? CAB=50？ ,? ABC= 100？ And then what? The degree of CBE is _ _ _ _ _ _ _.
17. Make a statistical analysis of the results of a class math exam (the score is a positive integer, and the full score is 100). The number of people in each fraction is shown in the figure (each group contains the previous boundary value, but does not contain the latter boundary value), and the frequency of this group is _ _ _ _ _ _ _. The frequency is _ _ _ _ _ _.
18. Company A buys two kinds of purified water, A and B, with 250 yuan, in which A water is 8 yuan per barrel, B water is 6 yuan per barrel, and the number of barrels of B water is 75% of A water's' barrels. Assuming that A water is X barrel and B water is Y barrel, the equation listed is as follows:
___________________________
Third, the solution (this big title is ***9 small questions, ***76 points, the solution requires writing instructions to prove the process or calculation steps)
19. (The full mark of this question is 8)
Calculation: (1); (2)
20. (The full mark of this question is 8)
Solve the inequality group and express the solution set on the number axis.
2 1. (The full mark of this question is 6)
Simplify first, then evaluate
, where y=2.
22. (The full mark of this question is 8)
factoring
( 1)
23. (The full mark of this question is 6 points)
As the picture shows, there is a beautiful and lovely little goldfish in the square.
(1) If the side length of the square is 1, the area of the small fish is.
(2) After the small fish is translated to the left by 10 squares, draw the figure of the small fish (drawing steps and processes are not needed).
24. (The full mark of this question is 8)
As shown in the figure, at △ABC,? B=54？ , AD split equally? Cab, pass BC at D, pass E at AC side, connect de,? EAD=？ EDA，EF？ BC is at point F.
Beg? The extent of the fed.
25. (The full mark of this question is 10)
A clothing store bought two kinds of new clothes, A and B, at the price of 10000 yuan. After selling them at the marked price, it can get a gross profit of 5400 yuan (gross profit)
Run = selling price-buying price), the buying price and the marked price of these two kinds of clothes are shown in the table:
Types and prices Type A and Type B
Purchase price (RMB/piece) 80 100
List price (RMB/piece) 120 160
(1) The number of pieces purchased for each of these two kinds of garments;
(2) Clothing A is sold at a 20% discount on the list price. If the gross profit of this batch of clothing is not less than 2,000 yuan after all sales, how much discount can clothing B get at most?
26. (The full mark of this question is 10)
A new operation T is defined for X and Y, and it is stipulated that: T(x, y)= (where A and B are nonzero constants), where the right side of the equation is the usual four operations, such as: t (0, 1) = = 2b- 1.
(1) It is known that T( 1,-1)=-2 and t (4,2) = 3.
① find the values of a and b;
(2) If the inequality group about m has exactly two integer solutions, find the range of the number p;
(2) If T(x, y)=T(y, x) is true for any real numbers x and y (where both T(x, y) and T(y, x) are meaningful), what kind of relationship should A and B satisfy?
27. (The full mark of this question is 12)
(1)AB‖CD, as shown in figure 1, when point p is outside AB and CD, AB‖CD, and? B=？ Bode, again? BOD is the outer corner of △POD, so? BOD=？ BPD+？ D, have to? BPD=？ B-？ D. as shown in figure 2, move point p into AB and CD. Is the above conclusion valid? If not, then? BPD？ B, is it? What is the quantitative relationship between d? Please prove your conclusion.
(2) As shown in Figure 3, if AB and CD intersect at Q, then? BPD？ B, is it? D, is it? What is the quantitative relationship between BQD (unproven)?
(3) According to the conclusion of (2), find the value in Figure 4. A+？ B+？ C+？ D+？ E+？ The degree of F.
(4) If there are points A 1, A2, A3, A4, A5, A6, A7, A8 on the plane, connect A 1A3, A2A4, A3A5, A4A6, A5A7, A6A8, A7 A 1, A8 A2, as shown in Figure 5. A 1+？ A2+？ A3+？ A4+？ A5+？ A6+？ A7+？ To what extent is A8 (direct writing grade)?
If there are n points A 1, A2, A3, A4, A5 And an on the plane, and the polygon surrounded by these n points is a convex polygon, connecting A 1A3, A2A4, A3A5A7, An- 1A 1, AnA2, then a/kloc. A2+？ A3+？ A4++？ An- 1+？ What is the number of An (direct writing of results, expressed by algebraic expressions containing n)?