Beijing normal university printing plate seventh grade mathematics volume one final examination paper topic
1. Multiple choice questions: (Only one of the four options in this big question *** 12 is correct. Please choose the correct option and fill in its letter number on the answer sheet).
The reciprocal of 1 -20 15 is ()
A.﹣20 15﹣
2. As shown in the figure, it is a cubic expansion diagram. After the unfolded diagram is folded into a cube, What about you? The word opposite the word is ()
A. China's dream
3. The following operation is correct ()
A.3a+2b = 5ab b . 3a2b﹣3ba2=0 c . 3 x2+2 x3 = 5x 5d . 3m4﹣2m4= 1
4. The solution of equation 3x-6 = 9 is ().
A. 5BC 65438+ 0BC-2
5. For the monomial, the following statement is true ()
A.this is a quartic monomial. Its coefficient is
C. it is a cubic monomial D. Its coefficient is
6. The following statement is true ()
A. extend light OA to point B.
The b line segment AB is a part of the straight line AB.
C. draw a straight line so that its length is 3 cm.
D. ray AB and ray BA are the same ray.
7. The positions of real numbers A and B on the number axis are as shown in the figure, so the following conclusion is correct ().
A.a+b & gt； 0b . a﹣b>； 0 C. a？ b & gt0d . >； 0
In order to celebrate the opening anniversary of a large supermarket in our county, all the goods are sold at a discount. A counter in this supermarket sells schoolbags at a price of 130 yuan at a 20% discount, and still makes a profit of 30%. The purchase price of each schoolbag is ().
A.65 yuan B. 80 yuan C. 100 Yuan D. 104 Yuan
9. It is known that |a|=3, |b|=5 and a >；; B, then the value of a+b is ()
A.2 or 8 b.2 or 8 C. 2 or 8 D. 2 or 8.
10. As shown in the figure, the straight line AB and CD intersect at point O, and the ray OM is equally divided. AOC，？ MON=90？ . What if? MOC=35？ 20? And then what? The bonding degree is ()
A.35? 20? B. 45？ 20? C. 54？ 40? D. 64？ 40?
1 1. If a polynomial is added with 5x2-4x-3 to get -x2-3x, then this polynomial is ().
A.4x2﹣7x﹣3·6x2﹣x﹣3·﹣6x2+x+3·﹣6x2﹣7x﹣3
12. When solving the equation, Xiao Ming accidentally polluted a constant in the equation and could not see it clearly. The equation of pollution is 2y﹣ = y﹣, what should I do? Xiao Ming thought for a moment, and then read the answer at the back of the book. The solution of this equation is y=﹣. This constant will be completed soon and should be ().
A. 1 B. 2 C. 3 D. 4
Second, fill in the blanks:
13. If the monomials 2x2ym and ﹣3xny3 are similar terms, the value of m+n is.
14. Liaoning, the Chinese aircraft carrier, is the first aircraft carrier capable of carrying fixed-wing aircraft in China People's Navy, with a full displacement of 67,500 tons, which can be expressed by scientific notation.
15. As shown in the figure, stack a pair of triangular plates together so that the right-angle vertex coincides with O, then? AOC+？ DOB=。
16. It is known that the solution of equation X = 10 ~ 4x is the same as that of equation 8x+5m= 1 1, so m=.
17. The speed of the ship in still water is 20 kilometers per hour, and the current speed is 4 kilometers per hour. It takes * * * 5 hours (excluding the stay time) to find the distance between two terminals. If the distance between two terminals is x km, the equation can be listed.
.
18. If the value of polynomial 2x2+3x+7 is 10, then the value of polynomial 6x2+9x-7 is.
Third, answer the question: (This big question is ***8 small questions, please write the necessary deduction process when answering the question)
19. Calculation:
(1) calculation: (-2) 3? (﹣ )+(﹣25)? (﹣ )2+(﹣ 1)20 15
(2) Calculation: 6+ 18-+(-)- 18+3
(3) The complementary angle of an angle is 30 smaller than this angle? Please work out the size of this angle.
20. Calculation
(1) It is known that A and B are reciprocal, and C and D are reciprocal.
(2) Calculation: (3A2-AB+7)-(4A2+2AB+7)
The positions of points A, B and C on the axis of 2 1. are shown in the figure. Point C is the midpoint of line segment AB, and the number represented by point A is three times larger than that represented by point C, while the numbers represented by point B and point C are opposite. Find the number represented by point C.
22. As shown in the figure, it is known that the line segment AB=8cm, the point E is on AB, and AE= AB. Extend line segment AB to point C so that BC= AB, and point D is the midpoint of BC, and find the length of line segment DE.
23. The following is the process of Liu Ying solving equations. Please observe whether there are any mistakes in solving the equation, and draw a curve under the mistakes. ~~~? , and indicate the cause of the error in brackets, and then write the correct process of solving this equation on the right side of the dotted line.
Solution:
If you divide by the denominator, you get 4 (3x ~1) ~ 3 (x+1) = 6 (2x+3) ~1().
Without brackets, you get12x ﹣ 4 ﹣ 3x+3 =12x+18 ﹣1().
If you move the item, you get12x ~ 3x ~12x =18 ~1+4 ~ 3 ().
Merge，get-3x = 18()
Coefficient 1, and get. ()
The correct solution is:
24. It is known that a-2b = 7a2-7ab, and b =-4a2+6ab+7.
(1) How much is a?
② If |a+ 1|+(b﹣2)2=0, find the value of a 。
25. As shown in the figure, the direction of light OA is 15? Is the direction of light OB 40? ,? AOB=？ AOC and ray OD are reverse extensions of OB.
(1) The direction of ray oc is;
(2) Q? Degree of chemical oxygen demand;
(3) What if Ray OE shares it equally? Cod, please Degree of AOE
26. A communication company in Yangxin County provides customers with the following two charging methods (users can choose one):
(1) The call fee per minute is 0. 1 yuan;
(b) Monthly rental of 20 yuan, plus 0.05 yuan per minute.
(1) How many minutes does the user talk in February 65438+, and the cost is the same for both methods?
(2) Please explain how to choose the charging method to save money. (Just write the results directly. )
Beijing normal university printing plate seventh grade mathematics volume one final examination paper reference answer
1. Multiple choice questions: (Only one of the four options in this big question *** 12 is correct. Please choose the correct option and fill in its letter number on the answer sheet).
The reciprocal of 1 -20 15 is ()
A.﹣20 15﹣
Test center: countdown.
Analysis: According to the definition of reciprocal, the reciprocal of-2015 is-.
Answer: Solution: The reciprocal of 20 15 is.
So choose: C.
Comments: This paper mainly examines the definition of reciprocal, which needs to be mastered skillfully. It should be pointed out that:
The nature of reciprocal: the reciprocal of a negative number is negative, the reciprocal of a positive number is positive, and 0 has no reciprocal.
Definition of reciprocal: If the product of two numbers is 1, we call these two numbers reciprocal.
2. As shown in the figure, it is a cubic expansion diagram. After the unfolded diagram is folded into a cube, What about you? The word opposite the word is ()
A. China's dream
Test center: topic: people on opposite sides of the cube.
Analysis: Using the characteristics of the cube and its surface expansion diagram to solve problems.
Solution: Solution: This is a plane expansion diagram of a cube. * * * has six faces, among which? Me? With your face? Medium? Relative, face? what's up With your face? Country? Relative,? What about you? With your face? Dream? Relative.
Therefore, choose: d.
Comments: This question examines the figures on the opposite sides of the cube, pays attention to the spatial graphics of the cube, and answers the questions from the opposite side.
3. The following operation is correct ()
A.3a+2b = 5ab b . 3a2b﹣3ba2=0 c . 3 x2+2 x3 = 5x 5d . 3m4﹣2m4= 1
Test center: merge similar items.
Analysis: this question examines the merger of similar items; When merging similar items, the coefficients are added as coefficients, and the index of letters remains unchanged.
Solution: Solution: A, 3a and 2b are not similar items and cannot be merged; So, A is wrong;
b、3a2b﹣3ba2=3a2b﹣3a2b=0； Therefore, B is correct;
C, 3x2 and 2x3 are not in the same category and cannot be merged; So, c is wrong;
d、3m4﹣2m4=m4； So, d is wrong.
So choose B.
Comments: the concept of similar items is that items with the same letters and the same index of the same letters are similar items; Please note that items that do not belong to the same category cannot be merged.
4. The solution of equation 3x-6 = 9 is ().
A. 5BC 65438+ 0BC-2
Test center: Solve a linear equation.
Special topic: calculation problems.
Analysis: shift and merge the equations, change the x coefficient to 1, and solve.
Solution: Solution: Equation 3x-6 = 9,
Transfer and merger: 3x= 15,
Solution: x=5,
So choose one
Comments: This question examines and understands the linear equation of one variable, and its steps are: removing the denominator, brackets, merging moving terms, converting unknown coefficients into 1, and solving.
5. For the monomial, the following statement is true ()
A.this is a quartic monomial. Its coefficient is
C. it is a cubic monomial D. Its coefficient is
Test center: single item.
Analysis: According to the definition of the coefficient and degree of a single item, the numerical factor in a single item is called the coefficient of a single item, and the sum of the indexes of all letters is called the degree of a single item.
Answer: Solution: A. Although the exponent of 10 is 3, 10 is not a letter, and the sum of the exponents of all letters is 2+ 1=3, which is a cubic monomial. Therefore, it is wrong;
B, its coefficient is 0, so it is wrong;
C, correct;
D. mistakes.
So choose C.
Comments: When determining the coefficient and degree of monomial, it is the key to find out the coefficient and degree of monomial by decomposing a monomial into the product of a number factor and a letter factor.
6. The following statement is true ()
A. extend light OA to point B.
The b line segment AB is a part of the straight line AB.
C. draw a straight line so that its length is 3 cm.
D. ray AB and ray BA are the same ray.
Test sites: straight lines, rays and line segments.
Analysis: according to the definitions of ray, line segment and straight line, the options are analyzed and judged by exclusion method.
Solution: Solution: A, the ray cannot be extended, so it is wrong to extend the ray OA to point B, so this option is wrong;
B. The line segment AB is a part of the straight line AB, so this option is correct;
C, a straight line has no length, so it is wrong to draw a straight line to make its length 3cm, so this option is wrong;
D ray AB and ray BA are not the same ray, so this option is wrong.
So choose B.
Comments: This question examines straight lines, rays and line segments, which is the basic question. The concept and nature of memory is the key to solving problems.
7. The positions of real numbers A and B on the number axis are as shown in the figure, so the following conclusion is correct ().
A.a+b & gt； 0b . a﹣b>； 0 C. a？ b & gt0d . >； 0
Test site: number axis; Mixed operation of rational numbers.
Analysis: It can be seen from the meaning of the question that-1.