1. If sum is the opposite number, then =. ()
A. 14B。 - 14C.49D.-49
2. The following statement is incorrect ()
A. There is the smallest positive integer, but there is no smallest negative integer B. If a number is an integer, it must be a rational number.
C it is neither a positive rational number nor a negative rational number. D. A positive rational number and a negative rational number form a rational number.
3. For the rounded approximation, the following statement is correct ()
A. There are three significant figures, accurate to 1%. There are six significant figures, accurate to the number.
C. there are two significant figures, accurate to ten thousand places. D there are three significant figures, accurate to 1000.
4. In the following figures, the number of unequal groups is ()
①(-3)2 and -32②(-3)2 and 32③(-2)3 and -23④3 and ⑤(-2)3 and 3.
A.0 group B. 1 group C.2 group D.3 group
5. The following statement is true ()
A. The same angle is equal B. The distance between two points refers to the length of the line segment connecting the two points.
C. The shortest straight line between two points D. The distance the train travels from Hai 'an to Nantong is the distance from Hai 'an to Nantong.
6. If known, the value of is ()
A.25B.30C.35D.40
7. The four figures on the right of the figure below must not be the three-dimensional diagram of the left expansion diagram, but ().
8. Today, if you want to lay carpets on the top and both sides of the rostrum of the sports meeting (as shown in the shadow), how much carpet area do you need? ()
Asian Development Bank.
Second, fill in patiently. (3 points for each small question, * * * 30 points)
9. In a city, the morning temperature 12℃, rising by 2℃ in the afternoon, falling at midnight (24: 00) 15℃, and the midnight temperature _ _ _ _ _ _ _ _
10. On the number axis, the number represented by the point with a distance of 3 is _ _ _ _ _ _ _ _.
1 1. In descending order of x, the polynomial 3xy-5xy+y-2x is.
12. Xiaoming walked from A to B 10m, and Liang Xiao also walked from A to C 15m, so the degree of BAC is degrees.
13. If ∠ 1+∠3= 180, ∠2+∠4= 180 and ∠1= ∠.
The reason is.
14. As shown in the figure, ∠AOB is a right angle, ∠AOC=300, ∠BOD=600,
OM and ON are bisectors of ∠AOC and ∠BOD, respectively, and ∠MON equals _ _ _ _.
15. The speed of a ship sailing along the river is 30 km/h. If sailing along the river at the same speed for 3 hours is equal to sailing against the current for 5 hours, then the voyage of the ship drifting along the river for half an hour is 1 km.
16. The car is driving on the expressway at a speed of 72 kilometers per hour, heading for the silent valley. The driver honked his horn and heard an echo four seconds later. How far is the car from the valley? It is known that the speed of sound propagation in the air is about 340 m/s, assuming that the car is meters away from the valley when the echo is heard, according to the meaning of the question, the equation is listed as follows.
It is getting closer and closer to the final exam, which is a period to test our academic performance in a semester. For the study of mathematics in senior one, the editor reminds everyone to do more exercises. Let's take a look at this senior one math final exam!
First, multiple-choice questions (4 points for each small question, *** 12 points)
1.(20 12 Yichang senior high school entrance examination) As shown in the figure, the point on the number axis that represents the inverse of the number -2 is ().
A. point PB QC point. MD point n point.
2. The result of simplification -{-[+(-20 13)]} is ()
A.-20 13B.20 13
C.-D。
3. The reciprocal of a number is non-negative, and this number must be ().
A. positive number or zero B. non-zero number
C. Negative number or zero
Fill in the blanks (4 points for each small question, *** 12 points)
4. If the inverse of A is -(+2 1), then a = _ _ _ _ _ _
5. If -x=2, then-[-(-x)] = _ _ _ _ _.
6. Use "∧" and "∨" to represent a rule: (a∧b)=-b, (a∨b)=-a, such as (2 ∧ 3) =-3, (2 ∨ 3) =-.
Iii. Answering questions (***26 points)
7.(9 points) Simplify the following figure:
( 1)-[-(-2)].(2)+[-(-3)].
(3)-{-[+(-2)]}.(4)+[-(+4)].
(5)+{-[-(-)]}.(6)-{+[-(+ 1)]}.
8.(8 points) If there are 20 13 minus signs before 20 13, and every two minus signs are separated by "()", what is the final simplified result of this number? What if there is a minus sign of 20 14 in front? What kind of rules do you get from it?
Extension extension
9.(9 points) Discussion and analysis: the position of points representing rational numbers A and -a on the number axis relative to the origin.
17. Write a linear equation with one variable satisfying the following conditions: ① The coefficient of unknown quantity is; The solution of the equation is 3, and such an equation is.
18. Xiaohong painted the room and hired five workers. 10 day was completed. A certain paint was used150l, with a cost of 4,800 yuan and a paint area of 150m2. At the time of final settlement, there are the following schemes: Scheme 1: According to the work, each worker 30 yuan (65430. Option 2: According to the painting cost,' 30% of the painting cost is regarded as salary; Option 3: Pay 12 yuan per square meter according to the painting area; Please help Xiaohong's family to give an idea, and choose the scheme _ _ _ _ to pay the most cost-effective, RMB.
Iii. Answering questions (* * *
19. Calculation and simplification (3 points for each question, *** 12 points)
20. Solve the equation (3 points for each small question, ***6 points)
2 1.(5 points) The complementary angle of one angle is 18 degrees, which is twice as large as the other angles. Find the degree of this angle.
22.(6 points) If the value of polynomial has nothing to do with letters,
Find the value of algebraic expression.
23.(6 points) Given the line segment AB, extend the line segment AB to D reversely, so that AD = AB extends AB to C, and AC=3AB.
(1) Draw a picture according to the meaning of the question;
(2) If the length of DC is 2cm, the midpoint of AB is E, and the midpoint of BC is F, find the length of EF.
24.(6 points) As shown in the figure, the known point O is a point on the straight line AB, and OD and OE are,
Angle bisector of.
(1);
(2) Write the congruent angle in the figure;
(3) Is there any corner filling? If yes, please find out and explain the reasons.
25.(5 points) A math contest paper has 20 multiple-choice questions, and it is stipulated that you will get 5 points for doing one question correctly, and 5 points for not doing one question or doing one wrong question. I can't see it clearly here for printing reasons. 16 did the text correctly, but only got 76 points. Why?
26.(6 points) The oil import volume of an oil importing country decreased this month compared with last month, but the cost of importing oil this month was higher than last month due to the rising international oil price. Find out the percentage of oil price increase this month compared with last month.
27.(6 points) The fruit wholesale department of a city wants to ship a batch of fruits from a city to the city for sale. There are two modes of transportation: train and car, and 200 yuan/hour is lost during transportation. Other main reference data are as follows:
Average speed of means of transport on the way (km/h) Freight (yuan/km) Loading and unloading expenses (yuan)
Train 100 152000
Automobile 8020900
(1) If the total expenditure of cars is more than that of trains 1 100 yuan, do you know how many kilometers the distance between this city and a city is? Please solve this equation.
(2) If the distance from City A to City A is S kilometers, and you know that the delay time of train and bus on the road is 2 hours and 3. 1 hour respectively, if you are the manager of the fruit wholesale department in City A, if you want to transport this fruit to other areas for sale, which transportation mode would you choose to be more cost-effective?
28.(6 points) It is understood that the train fare is determined by the method of "". It is known that the total mileage from Station A to Station H is1500km, and the reference price for the whole journey is 180 yuan. The following table shows the mileage from stations along the way to H station:
Station name ABCDEFGH
The mileage (km) from each station to H station is15001kloc-0/30910622402219720.
For example, the fare from Mile Mile to E Station is (yuan).
(1) Find the train fare from Station A to Station F (accurate to 1 yuan);
(2) Passenger Aunt Wang takes the train from Station A to Station H to her daughter's house. After getting on two trains, she took the ticket and asked the flight attendant, am I near the station? When the flight attendant saw that the ticket price in Aunt Wang's hand was 66 yuan, she immediately said that the next stop was here. At which station does Aunt Wang get off? (Write the solution procedure)
This seventh grade math final exam is here to share with you. At the same time, the final papers of all subjects in Grade One are mostly in Grade Seven. I wish everyone can pass the exam smoothly!
Good news: QQ group 1 17367 168 was established to facilitate junior high school students from all over the country to learn and communicate with each other. Welcome students to join us as soon as possible! I hope that through this platform, our achievements will have a new breakthrough! ! !
The result of this semester's hard work depends on the result of the final exam, so we must pay attention to it. On the occasion of the final exam, all the students in Grade One have compiled a final exam paper and answers for Grade Seven mathematics, hoping to help the candidates!
First, multiple-choice questions (4 points for each small question, *** 12 points)
1. The inverse of the solution of equation 3x+6=0 is ().
A.2B.-2C.3D.-3
2. If 2x+ 1=8, the value of 4x+ 1 is ().
A. 15B
3. When a classmate solved the equation 5x- 1=□x+3, he misread the number at □ as x=-, and he took □ as ().
A.3B.-9C.8D.-8
Fill in the blanks (4 points for each small question, *** 12 points)
4. The solution of equation 3x+ 1=x is.
5. If the value of the algebraic expression 3x+7 is -2, then x=.
6.(20 12 Qianjiang Senior High School Entrance Examination) The school held a "Let's Sing and Dance" cultural performance, and set up two programs: singing and dancing. The teachers and students of the whole school performed 30 programs, of which singing programs were twice as few as dancing programs, so the teachers and students of the whole school performed 2 singing programs.
Iii. Answering questions (***26 points)
7.(8 points) Solve the following equations.
( 1)2x+3=x- 1。 (2)2t-4=3t+5。
8.(8 points) (20 12 senior high school entrance examination in Ya 'an) Wrap a rope around a cylindrical oil drum. If you circle the oil drum 3 times, the rope will be 4 feet more; If you circle the oil drum four times, the rope will be 3 feet shorter. How long is this rope? How many feet does it take to go around the oil drum?
Extension extension
9.( 10) Look at the examples first, and then solve similar problems.
Example: Solve equation |x|+ 1=3.
Method 1: when x≥0, transform the original equation into x+ 1=3, and solve the equation to get x = 2;; When x
Method 2: Shift the term to get |x|=3- 1, and merge similar terms to get |x|=2. In the sense of absolute value, we know that x=2, so the solution of the original equation is x = 2 or x=-2.
Question: Use the law you found to solve the equation: 2|x|-3=5. (Solve in two ways)