20 12. 1 1
1. Multiple choice questions: (2 points for each small question, *** 16 points)
1.2008 The number of seats in the "Bird's Nest" of the Beijing Olympic Games is 9 1000, which is expressed by scientific notation as ().
A.0.9 1× 105 b . 9. 1× 104 c . 9 1× 103d . 9. 1× 103
2. The following statement is true ()
A.–2 is a monomial B.–A stands for a negative number C. The coefficient is D. x++1 is a polynomial.
3. The following calculation is correct ()
A.B. C. D。
4. In the following groups, the equivalent usage is ()
A. and-16 b. and-(-3) C. and D.-1 and-1) n.
5. If the sum of a polynomial is equal to, then the polynomial is ().
A.B. C. D。
6. If and, it is equal to ()
A.4b. 10c.4d.4 or 10
7. If the polynomial about x contains no quadratic term, then m is equal to ().
a . 2 B- 2 c . 3d-3
8. As shown in the figure, cut a square with a side length of cm from a square paper with a side length of (a+4) cm, and cut the rest into rectangles along the dotted line (no overlap and no gap), then the area of the rectangle is ().
A.B. C. D。
Fill in the blanks: (3 points for each small question, *** 15 points)
9. A rational number with a square of 9 is _ _ _ _ _ _ _ _.
10. The coefficient of single item-is _ _ _ _ _ _, and the degree is _ _ _ _ _.
1 1. If 3xym+n and-2x2my3 are similar terms, then m-n = _ _ _ _ _ _
12. Approximation 2. 13 is accurate to _ _ _ _ _.
13. Given that the value of x2-4x+6 is 9, the value of 6-3x2+ 12x is _ _ _ _ _.
Third, the calculation questions: (5 points for each small question, ***25 points)
14.
15.-0.252÷
16.
17.
18. Xiao Ming calculated this way:
== - 12- 18+8=-22
Did he do the right thing? If not, please write the correct calculation process.
Iv. Answer: (19-24 questions, 6 points for each small question and 8 points for 25 questions)
19. As we all know, the sum of sum is a monomial. Find the sum of these two monomials.
20. Simplified assessment:, in which
2 1. Known, try to find the value.
22. Xiaoming is known to be years old, Xiaohong is several years younger than Xiaoming, and Xiaohua is younger than Xiaohong.
Some students are still in their teens. Please find out the sum of the ages of these three students.
23. Explore the law:
(1) Observe with the following numbers: 3, 6, 10, 15, 2 1, ... Please find out the arrangement rule and follow this rule.
Fill in the blanks. The ninth number is _ _ _ _ _ _ _, and the nth number is _ _ _ _ _ _.
(2) given the number of columns: 1, -2, 3, -4, 5, -6, 7, ... arrange the numbers into a triangular digital array:
1
-2 3
-4 5-6
7 -8 9 - 10
1 1 - 12 13- 14 15
… …
According to the above rules, the fifth number from the left of line 10 is, and the sum of lines 100 is.
____________.
24. As we all know, | 3-(-2) | represents the absolute value of the difference between 3 and -2, and its significance on the number axis is the distance between the point representing 3 and the point representing -2. Try to explore:
( 1) Find | 3-(-2) | = _ _ _ _ _。
(2) The formula |x+3| has the meaning of _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
(3) Find all qualified integers X, so that the integer | x+3 | | x-2 | = 5 is _ _ _ _ _ _ _ _ _ _ _.
25.(8 points) The school organizes students to visit museums. Xiao Ming didn't leave with his classmates at the same time because of something. He was going to take a taxi at the school gate to pick up his classmates. The taxi fare standard is: the starting price is 6 yuan, and the fare per kilometer after 3 kilometers is 1.2 yuan. If it is less than 1 km, it shall be calculated as 1 km. Please answer the following questions:
(1) Xiaoming took a 3.8-kilometer bus and should pay _ _ _ _ _ _ _ yuan. ..
(2) How much does it cost for Xiaoming to take bus x(x is an integer greater than 3) kilometers?
(3) Xiaoming only has 10 yuan. Is it enough to take a taxi from school to the museum 7 kilometers away?
Please provide a justification for the answer.
test paper
1. Multiple choice questions: (2 points for each small question, *** 16 points)
1
2
three
four
five
six
seven
eight
B
A
D
B
B
D
C
D
Fill in the blanks: (3 points for each small question, *** 15 points)
9.3. 10., 4. 1 1.- 1. 12.00 13.-3.
Third, the calculation questions: (5 points for each small question, ***25 points)
14.
Solution: Original formula =...( 1)
=...(3 points)
=-2-4+=-5 ...(5 points)
15.-0.252÷
Solution: Original formula =-(.....(2 points)
=-( 18+28-45) ...(4 points)
= =-...(5 points)
16.
Solution: The original formula = (5-3-2) x+(-5+6) x+(4-5)...(2 points)
= X- 1...(5 points)
17.
Solution: Original formula =...( 1)
=...(3 points)
=...(5 points)
18. Xiao Ming calculated this way:
== - 12- 18+8=-22
Did he do the right thing? If not, please write the correct calculation process.
Solution:No.. .....( 1)
= (-6)-(2 points)
=(-6)÷
= (-6) × 12 ...(4 points)
=-72 ...(5 points)
19. As we all know, the sum of sum is a monomial. Find the sum of these two monomials.
Answer: According to the meaning of the question, and are similar projects ... (1)
∴ n-m = 3, m+ 1 = 2...(3 points)
∴+() = () ...(5 points)
=...(6 points)
20. Simplified assessment:, in which
Solution:
=...(2 points)
=-...(4 points)
Original formula at that time =-...(5 points)
= =-3 ...(6 points)
2 1. Known, try to find the value.
Solution:
∴ ...( 1 min) = 0...(4 points)
Again =-3A+B2...(5 points)
∴ A+ 1 = 0, 2a-b = 0 when A =- 1, B =-2,
∴ A =- 1, B =-2...(2 points) Original formula =-3× (- 1)+(-2) 2.
= 3+4 = 7 ...(6 points)
22. Solution: Xiaohong is old and Xiaohua is old.
So the total age of these three students is
..... (3 points)
..... (5 points)
...... (6 points)
23. Explore the law:
(1) Observe with the following numbers: 3, 6, 10, 15, 2 1, ... Please find out the arrangement rule and follow this rule.
Fill in the blanks. The ninth number is 55, and the nth number is (1, 1, 2,2).
(2) given the number of columns: 1, -2, 3, -4, 5, -6, 7, ... arrange the numbers into a triangular digital array:
1
-2 3
-4 5-6
7 -8 9 - 10
1 1 - 12 13- 14 15
… …
According to the above rules, the fifth number from the left of line 10 is -50, and the sum of lines 100 is
-50.( 1 space is 1, and the second space is 2)
24. As we all know, | 3-(-2) | represents the absolute value of the difference between 3 and -2, and its significance on the number axis is the distance between the point representing 3 and the point representing -2. Try to explore:
( 1) Find | 3-(-2) | = 5。
(2) The meaning of the formula |x+3| on the number axis is the distance between the point representing x and the point representing -3.
(3) Find all qualified integers X, so that integers such as | x+3 | | x-2 | = 5 are -3, -2,-1, 0, 1, 2.
... =' class1' > (1) 1, (2) 2, (3) 3, (3) 1 for two correct questions, 0 for 1 wrong questions ...
25.(8 points) The school organizes students to visit museums. Xiao Ming didn't leave with his classmates at the same time because of something. He was going to take a taxi at the school gate to pick up his classmates. The taxi fare standard is: the starting price is 6 yuan, and the fare per kilometer after 3 kilometers is 1.2 yuan. If it is less than 1 km, it shall be calculated as 1 km. Please answer the following questions:
(1) Xiaoming rides 3.8km and should pay 7.2 yuan. ..... (2 points)
(2) How much does it cost for Xiaoming to take bus x(x is an integer greater than 3) kilometers?
(3) Xiaoming only has 10 yuan. Is it enough to take a taxi from school to the museum 7 kilometers away?
Please provide a justification for the answer.
Solution: (2) 6+(x-3) × 1.2...(3 points)
=6+ 1.2x-3.6
= 1.2x+2.4...(4 points)
A: The fee payable is (1.2x+2.4) yuan. ..... (5 points)
(3) The fare is not enough ... (6 points)
The fare to 7 km by bus is 6+(7-3) × 1.2.
= 6+4.8 = 10.4 (yuan) ... (7 points)
∵ 10﹤ 10.4
The fare is not enough. ..... (8 points)