The square root of 1. 1 is ()
A.0 B. 1 C？ 1 D.﹣ 1
2. In the plane rectangular coordinate system, the point p (-5,0) is in ().
A. In the second quadrant B.x axis C. In the fourth quadrant D.y axis.
3. In order to know the weight of 300 freshmen in a school, 50 students were selected for statistical analysis. In this question, the general meaning is ().
A.300 students B. Choose 50 students
C.C.300 Weight of 300 students D. Weight of 50 students.
4. A store sells 16 shirts, 19 shirts, 15 shirts, 18 shirts, 22 shirts, 30 shirts and 26 shirts every day for a week. In order to reflect the changes of shirts sold this week, we should make a statistical chart ().
A. Sector statistics B. Strip statistics C. Broken line statistics D. Histogram
5. Estimate the value of -2 ()
A. 1 and 2, b. 2 and 3, c. 3 and 4, d. 4 and 5.
6. As shown in the figure, the straight line a∨b,? 1= 120? ,? 2=40? And then what? 3 equals ()
.60 caliber? B.70？ C.80？ D.90？
7. Move point A (2, -2) up by 4 units to get point B, and then move point B to the left by 4 units to get point C, then the following statement is correct ().
① The coordinates of point C are (-2,2).
② Point C is on the bisector of the second quadrant and the fourth quadrant;
③ The abscissa and ordinate of point C are opposite;
④ The distances from point C to the X axis and Y axis are equal.
1。
8. The following statement: ①-2 is the square root of 4; ② The square root of16 is 4; ③ The square root of125 is15; ④ The arithmetic square root of 0.25 is 0.5; What is the cube root of ⑤? ; The square root of 6 is 9, in which the correct statement is ()
1。
9. An exam, a class's math score chart is as follows. The following statement is wrong ()
A. The number of people with scores between 70 and 80 is the highest.
The number of students in this class is 40.
C The number of people with a score between 90 and 100 is the least.
D. adopt (? The number is 26.
10. Given points A (1 0) and B (0 0,2), point P is on the X axis, and the area of △PAB is 5, then the coordinate of point P is ().
A.C. D。
1 1. There are ***20 questions in a knowledge contest, and each question gets 10 for correct answer, and 5 points will be deducted if the answer is wrong. Xiaoying's score is not less than 90 points. If she answers question X correctly, according to the meaning of the question, the inequality can be listed as ().
A. 10x﹣5(20﹣x)？ 90 b. 10x﹣5(20﹣x)>； 90 C. 10x﹣(20﹣x)？ 90 d. 10x﹣(20﹣x)>； 90
12. The sum of all integer solutions suitable for inequality groups is ()
A.-165438 BC
Fill in the blanks (***6 small questions, 4 points for each small question, out of 25 points)
13. The solution set of the inequality group is.
14. If point A (a, 3) is on the Y axis, then point B (a-3, a+2) is in the fourth quadrant.
15. It is known that it is the solution of binary linear equations, then the square root of m﹣n is.
16. There are 40 students in one class and one math exam. 18 students are excellent. In the pie chart, the degree of the fan-shaped central angle representing the percentage of outstanding students is.
17. Let the real numbers x and y satisfy the equation, then x-y =.
18. It is known that there are only four integer solutions to the inequality group about x, so the norm of real number A is.
Third, answer questions (***6 small questions, out of 39 points)
19. Solve the equation:
( 1) ;
(2) .
20. Solve the inequality group and write the integer solution of the inequality group.
2 1. Primary and secondary school students in our city? My Chinese dream? In the reading activity, a proofreader gave some students the theme? My favorite book? In the survey activities, books are divided into four categories: A, B, C and D. Students can choose any one of them according to their hobbies. According to the investigation, the school made statistics and drew incomplete histogram and fan chart.
Please answer the following questions according to the information in the picture ((1) and (2) just fill in the answers directly):
(1) This * * * survey of students;
(2) Among the students surveyed, the ones who like D books the most, and the ones who like A books the most account for% of the surveyed;
(3) Among the students who like C books best, the number of girls is 1.5 times that of boys. If there are about 1800 students in this school, please estimate the number of girls and boys who like C books best in this school.
22. The square roots of a positive number x are 2a-3 and 5-a, and find the values of a and x. 。
23. As shown in the figure, it is known that AD∨BC,? 1=? 2. Verification:? 3+? 4= 180? .
24. As shown in the figure, each small square of square paper is a square with a side length of 1 unit length. In the plane rectangular coordinate system, points A (1 0), B (5 5,0), C (3 3,3), D (1 4).
(1) Track the positions of four points A, B, C and D, and connect A, B, C and D in turn;
(2) The area of quadrilateral ABCD is; (Write results directly)
(3) Translate the quadrilateral ABCD to the left by 6 units, and then translate it by 1 unit to get the quadrilateral A? b？ c？ d？ Draw a quadrilateral a in the picture? b？ c？ d？ And write one? b？ c？ d？ [(1)(3) Pictures are in the same coordinate system].
The second volume of the seventh grade refers to the answer to the final examination paper of mathematics 1. Multiple choice questions (*** 12 small questions, 3 points for each small question, out of 36 points).
The square root of 1. 1 is ()
A.0 B. 1 C？ 1 D.﹣ 1
Analysis According to the definition of square root, find the square root of the number A, that is, find a number X, so that x2=a, then X is the square root of A, so the problem can be solved.
Solution: ∫ (? 1)2= 1,
? What is the square root of 1? 1.
So choose: C.
The commentary on this topic examines the definition of square root. Note that a positive number has two square roots, and the two square roots are in opposite directions; The square root of 0 is 0; Negative numbers have no square root.
2. In the plane rectangular coordinate system, the point p (-5,0) is in ().
A. In the second quadrant B.x axis C. In the fourth quadrant D.y axis.
Analysis can be judged according to the coordinate characteristics of points.
Solution: In the plane rectangular coordinate system, the point P (-5,0) is on the X axis.
So choose B.
Comment on this question. Mastering the characteristics of this point in the plane rectangular coordinate system is the key to solve this problem.
3. In order to know the weight of 300 freshmen in a school, 50 students were selected for statistical analysis. In this question, the general meaning is ().
A.300 students B. Choose 50 students
C.C.300 Weight of 300 students D. Weight of 50 students.
Do such problems need to be analyzed and solved? In fact, the object of investigation should be the data representing a certain feature of things, not the things under investigation. When we distinguish the four concepts of population, individual, sample and sample size, we must first find out the object of investigation, so as to find out the population and individual, and then find out the sample according to the object of this part of the collected data.
Solution: The object of this question is the weight of 300 first-year students in a school.
So the overall situation is that a school is 300 students taller.
So choose C.
To comment on this question is to determine the whole. The key to solving specific problems is to distinguish the whole, the individual and the sample. The respondents of the whole, the individual and the sample are the same, and the difference is only the size of the scope.
4. A store sells 16 shirts, 19 shirts, 15 shirts, 18 shirts, 22 shirts, 30 shirts and 26 shirts every day for a week. In order to reflect the changes of shirts sold this week, we should make a statistical chart ().
A. Sector statistics B. Strip statistics C. Broken line statistics D. Histogram
The analysis shows that the percentage of parts in the total number is represented by fan-shaped statistical chart, but it is generally impossible to obtain specific data directly from the chart;
The dotted statistical chart shows the change of things;
Bar charts can clearly show the specific figures of each item;
Histogram can clearly show the specific number of each group, and the data is continuous when grouping; Can analyze the answer.
Solution: According to the characteristics of statistical chart, know
The dotted line chart shows the change of things, which can reflect the change of shirts sold this week.
So choose C.
The comment on this question examines the nature of statistical charts. The key to solve this problem is to judge according to the characteristics of fan-shaped statistical chart, broken-line statistical chart, bar-shaped statistical chart and histogram.
5. Estimate the value of -2 ()
A. 1 and 2, b. 2 and 3, c. 3 and 4, d. 4 and 5.
Analyze the estimated value first, then estimate -2, and you can solve it.
Solution: ∫5
? 3 & lt﹣2<； 4,
So choose: C.
Comment on this problem is to estimate the size of irrational numbers, and the key to solve this problem is the estimated value.
6. As shown in the figure, the straight line a∨b,? 1= 120? ,? 2=40? And then what? 3 equals ()
.60 caliber? B.70？ C.80？ D.90？
By a∨b analysis, according to the nature of parallel lines? 1=? 4= 120? And then according to the nature of the triangle outer angle? 4=? 2+? 3, so? 3=? 4﹣? 2=80? .
Solution: As shown in the figure,
∫a∨b，
1=? 4= 120? ,
∵? 4=? 2+? 3,
And then what? 2=40? ,
? 120? =40? +? 3,
3=80? .
So choose C.
This topic examines the properties of parallel lines: two straight lines are parallel and the same angle is equal. It also investigates the properties of the external angles of triangles.
7. Move point A (2, -2) up by 4 units to get point B, and then move point B to the left by 4 units to get point C, then the following statement is correct ().
① The coordinates of point C are (-2,2).
② Point C is on the bisector of the second quadrant and the fourth quadrant;
③ The abscissa and ordinate of point C are opposite;
④ The distances from point C to the X axis and Y axis are equal.
1。
First, we can get C (2-4, -2+4) according to the translation method, then get the coordinates of point C, and then analyze four sentences according to the coordinates of point C. 。
Solution: Move point A(2, ﹣2) up by 4 units to get point B(2, ﹣2+4).
Namely (2, 2),
Then move point B to the left by 4 units to get point C (2-4,2).
Namely (-2,2),
① The coordinate of point C is (-2,2), which is correct;
② Point C is on the bisector of the second quadrant and the fourth quadrant, which is correct;
③ The abscissa and ordinate of point C are opposite and correct;
④ The distances from point C to X axis and Y axis are equal and correct.
Therefore, choose: d.
Comments on this topic mainly focus on translation transformation and coordinate transformation; The key is to master the abscissa, add right and subtract left; The ordinate, up, down.
8. The following statement: ①-2 is the square root of 4; ② The square root of16 is 4; ③ The square root of125 is15; ④ The arithmetic square root of 0.25 is 0.5; What is the cube root of ⑤? ; The square root of 6 is 9, in which the correct statement is ()
1。
Analysis can be based on square root, arithmetic square root and cubic root.
Solution: ①-2 is the square root of 4, correct; ② What is the square root of16? 4, so it is wrong; ③ The square root of-125 is -5, so it is wrong; ④ The arithmetic square root of 0.25 is 0.5, which is correct; The cube root of ⑤ is, so it is wrong; 6 = 9, what is the square root of 9? 3, so it is wrong;
The correct statement is: ① ④, ***2,
Therefore, choose: B.
This topic reviews the square root, arithmetic square root and cube root. The key to solve this problem is to remember the square root, arithmetic square root and cube root.
9. An exam, a class's math score chart is as follows. The following statement is wrong ()
A. The number of people with scores between 70 and 80 is the highest.
The number of students in this class is 40.
C The number of people with a score between 90 and 100 is the least.
D. adopt (? The number is 26.
By analyzing and observing the histogram of frequency distribution, the number of people who scored 70-80 points was 14, the most;
The total number of people in this class is the sum of the number of people in each group;
The number of people who scored between 90- 100 was the least, with only 2 people;
Pass (? The number is 36.
Solution: A, the number of people with scores between 70 and 80 is the largest, so it is correct;
B, 2+4+8+ 12+ 14=40 (people), the total number of students in this class is 40, so it is correct;
C, the score between 90 ~ 100 is the least, and there are two people, so it is correct;
D, 40-4 = 36 (person), pass (? The number of people is 36, so D is wrong, so D is chosen.
Comment on this topic to investigate the ability to read the histogram of frequency distribution and the ability to obtain information by using statistical graphs; When using statistical charts to obtain information, we must carefully observe, analyze and study statistical charts in order to make correct judgments and solve problems.
10. Given points A (1 0) and B (0 0,2), point P is on the X axis, and the area of △PAB is 5, then the coordinate of point P is ().
A.C. D。
According to the coordinates of point B, we can know that the height on the edge of AP is 2, the area of △PAB is 5, and point P is on the X axis, that is, AP=5, so we can get the coordinates of point A..
Solution: ∫A( 1, 0), B (0 0,2), point P on the X axis,
? The height of the AP side is 2,
The area of delta delta δ△PAB is 5,
? AP=5，
Point p can be to the left or right of point a (1, 0),
? Page (abbreviation of page)
So choose C.
This topic uses the base, height and area of a triangle to investigate the coordinates of the midpoint in a rectangular coordinate system.
1 1. There are ***20 questions in a knowledge contest, and each question gets 10 for correct answer, and 5 points will be deducted if the answer is wrong. Xiaoying's score is not less than 90 points. If she answers question X correctly, according to the meaning of the question, the inequality can be listed as ().
A. 10x﹣5(20﹣x)？ 90 b. 10x﹣5(20﹣x)>； 90 C. 10x﹣(20﹣x)？ 90 d. 10x﹣(20﹣x)>； 90
The score of analyzing Xiaoying's correct answer is10x; Xiaoying's score for wrong or no answer: -5 (20-x). Unequal relationship: Xiaoying's score is not less than 90.
Solution: Assuming that she answered question X correctly, according to the meaning of the question, she got
10x﹣5(20﹣x)？ 90.
So choose a.
This review mainly examines the one-dimensional linear inequality abstracted from practical problems. Grasping the key words and finding the inequality relationship is the key to solving the problem.
12. The sum of all integer solutions suitable for inequality groups is ()
A.-165438 BC
Analyze and find the solution set of inequality group, find the integer solution of inequality group, and then add.
Solution:
∵ Solving inequality ①: x > ﹣ ,
Solve inequality ②: x? 1,
? The solution set of inequality system is