After studying for a semester, how did you learn? We want to know ourselves, so do teachers and parents. And this effect can be tested by exams. ? Review? It's not dispensable, we should do it well. The following is the final examination paper of the next volume of my seventh grade mathematics. I hope everyone will look carefully!
1. Multiple choice questions (This big question has ***8 small questions, and only one answer of each small question is correct. Please fill in the letters before the answers you think are correct in the corresponding spaces in the table below, with 3 points for each small question and * * * 24 points).
1. As we all know, if c is an arbitrary rational number, the following inequality always holds.
A.B. C. D。
2. put inequality? Represented on the number axis, it is correct.
3. Among the following four polynomials, the one that can be factorized is
A.a2+ 1 b . a2-2a+ 1 c . x2+5y d . x2-5y
4. The following operations are correct
A.B. C. D。
5. As shown in the figure, straight lines AB ‖ CD and EF intersect AB and CD at points M and N respectively. What if? AME= 125？ And then what? The degree of CNF is
A. 125？ B.75？ C.65？ D.55？
6. If the two sides of a triangle are 5cm and 7cm respectively, the length of the third side may be
A.2cm B.10cm C.12cm D.14cm
7. As shown in the figure, translate △ABC 3cm along BC direction to get △ D EF. If the perimeter of △ABC is 14cm, the perimeter of quadrilateral ABFD is
A.14cm B.17cm C. 20cm D. 23cm
8. Among the following propositions, ① the vertex angles are equal; ② The complementary angles of equal angles are equal; ③ If yes, then ④ is equal to the complementary angle. The number of true propositions is
1。
II. Fill in the blanks (this big question * * 10 small question, 2 points for each small question, 20 points for * * *)
9.？ The sum of 2 times x and 5 is not less than 10? Manifested as inequality.
10. What is the sum of the external angles of a heptagon? .
1 1. Proposition? If so, then ...? The inverse proposition of is.
12. The mass of a drop of water is about 0.0000 5 kg. The data of 0.00005 is expressed by scientific notation.
13. Calculation: =.
14. If the algebraic expression can be replaced by, the value of is.
15. If the solution of the equation is satisfied, the value of m is.
16. As shown in the figure, put a ruler and a triangular ruler as shown in the figure. What if? 1=55? And then what? 2. To what extent? .
17. As shown in the figure, after cutting a square paper with a side length of 2m+3 into a square with a side length of m+3, the rest can be cut and spliced into rectangles. If one side of the mosaic rectangle is m and the other side is m.
18. As shown in the figure, extend the AB side of △ABC twice to point A 1, BC side twice to point B 1 and CA side twice to point C 1, and connect A 1 and B 1 in turn. Then extend △A 1B 1C 1 twice on each side to get △A2B2C2, and so on to get △ anbcnn. If the area of △ABC is 1, the area of △ anbcnn is.
Iii. Answering questions (this topic is ***8 small questions, 19 and 20 are 8 points each; 2 1, 22 6 points for each small question; 23, 24, 8 points for each small question; The 25th question is 10, and the 26th question is 12, ***66).
19.( 1) Calculation: (-2a2b2)2? a2b？ -2a(a-3)
(2) simplify first? (a+ 1)+, and then a selects an appropriate number from-1, 1, 2 for evaluation.
20. Solve the following equation (group)
( 1) - 1= (2)
2 1. Teacher Zhang's phone bill for one month is as follows. Please answer the following questions according to the chart information:
Project monthly function fee, basic telephone fee, long-distance telephone fee and short message fee.
Amount/Yuan 5
(1) Please complete the table and bar chart;
(2) How much did Mr. Zhang spend on his mobile phone this month?
(3) In the sector statistics chart, what is the central angle of the sector representing the short message?
22. Fill in the blanks according to the picture:
Known: DAF=F,? B=？ d，
Evidence: DC.
Proof: ∫ daf = f (_ _ _ _ _ _),
? AD‖BF(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _)，
D=？ DCF(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _)，
∵? B=？ d(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _)，
B=？ DCF(_________________________)，
? AB‖DC(_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _)。
23. Read the following materials first, and then solve the problem:
Reading materials: Because (x-2)(x+3)=x2+x-6, so (x2+x-6)? (x-2)=x+3, that is, x2+x-6 can be
X-2 is divisible, so x-2 is a factor of x2+x-6. When x=2, x2+x-6=0.
(1) Analogical thinking: (x+2)(x+3)=x2+5x+6, then (x2+5x+6)? (x+2)=x+3, that is, x2+5x+6 can be divisible by _ _ _ _ _ _ _, so _ _ _ _ is a factor of x2+5x+6, and when x=_____, x2+5x+6 =
(2) Inquiry: According to the above materials, it is known that the polynomial x2+mx- 14 can be divisible by x+2, and try to find the value of m. 。
24. It is known: As shown in the figure, AB‖CD and BD are equally divided? ABC, CE split equally? DCF，？ ACE=90？ .
(1) Are BD and CE parallel? Please explain the reason;
(2) 2) What is the positional relationship between AC and BD? Please explain the reasons for your judgment.
25. An electric supermarket sells two types of electric fans, A and B, each at a price of 200 yuan, 170 yuan. As shown in the table, the sales in the last two weeks are as follows: (the purchase price and selling price remain unchanged, and profit = sales revenue-procurement cost).
Sales time, sales quantity and sales revenue
Model a and model b
The first week 3 5 1800 yuan.
The second week is 4 10 3 100 yuan.
(1) Find the sales unit price of two models of electric fans A and B;
(2) If the supermarket purchases 30 electric fans of these two models and all of them are sold out, can the supermarket achieve the profit target of 14000 yuan? If yes, please give the corresponding purchasing plan; If not, please explain why.
26. in order to pass smoothly? National civilized city? After acceptance, the municipal government plans to completely transform some public facilities such as sidewalk tiles, green belts and drainage pipes. According to the needs of municipal construction, the project needs to be completed within 40 days. At present, two engineering teams, A and B, are interested in contracting this project. According to the investigation, the time for Team B to complete this project alone is twice as long as that for Team A. If two engineering teams cooperate, it only takes 10 days.
(1) How many days will it take for Party A and Party B to complete this project alone?
(2) If the daily cost of construction team A is 45,000 yuan, and that of construction team B is 25,000 yuan, please design a scheme that can not only finish the project on time, but also minimize the project cost?
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