1, which of the following statements is incorrect ()
A. if x=y, then x+5 = y+5b. If x=y, then
C.if-3a =-3b，a = b d. if x-，x = y。
2. If equation (2a+ 1)x2+bx+c=0 is a linear equation about x, then the values of letter coefficients a, b and c must satisfy ().
A.a = any number B.
C.d. is an arbitrary number.
3. Known equation: ① 3x-1= 2x+1; ②x+=③④ The equation whose solution is x=2 is ().
A.①②③ B.①③④
C.②③④ D.①②④
4. It is known that y= 1 is the solution of equation 2-, so the solution of equation m (x-3)-2 = m (2x-5) about x is ().
A.x=- 10 B.x=0
C.x= D.x=
5. It is known that A is an integer other than 0, and the equation ax=2a3-3a2-5a+4 about X has an integer solution, so the value of A * * * has ().
A. 1 B.3
C.6 D. 9
6. The purchase price of a commodity purchased by a store is 8 yuan/piece, and the sales price is 10 yuan/piece. Now, in order to expand sales, the sales price of each item is reduced by x%, but the profit from selling a commodity is required to be 90% of the profit before the price reduction, so X should be equal to ().
A. 10
C.2 D. 1
7, the implementation of the western development is an important decision of the CPC Central Committee facing the 2 1 century, the western region accounts for about 9.6 million square kilometers of China's land area, and the area of China's western region is about () by scientific notation.
A.640× 104 km2 B.64× 105 km2
C.6.4× 106 km2 D.6.4× 107 km2
8. As shown in the figure, if the whole circle represents 36 tons of soybeans, then sector C represents soybeans ().
36 tons 18 tons
C. 13.5 tons D.4.5 tons
9. In a bag, there are six red balls, three white balls and three black balls. Every ball is the same except the color. If you touch a ball at will, the ball that is most likely to be touched is ().
A. Red ball B. White ball
C. Black ball D. Not sure
10. A railway line has stations in six cities: A, B, C, D, E and F. In order to travel between these six cities, different tickets should be prepared on the railway ().
A.20 species B. 30 species
C.40 species D. 50 species
Second, fill in the blanks
1 1, if the equation about x (k-2)x|k- 1|+5k=0 is a linear equation, then k = _ _ _ _ _
12. If the equations 2ax+27=0 and 2x+3a=0 about x have the same solution, then their same solution is X = _ _ _ _ _
13. if the equation a(2x+b)= 12x+5 about x has countless solutions, then A = _ _ _ _, and B = _ _ _ _.
14. It is known that the equation 9X-3 = KX+ 14 about x has an integer solution, so all integers K = _ _ _ _ _.
15,2003xn+7 and 199x2m+3 are similar terms, so (2m-n) 2 = _ _ _ _.
16. Given that the algebraic expression x2-2kxy-3y2+xy-x+8 contains no xy term, then k = _ _ _ _ _.
17, let A = 9.85× 10 10, and b =1.08×101,then the size relationship between a and b is _ _
18. If an ant covers an area of 2mm2, 1 10,000 ants cover an area of _ _ _ _ cm2 or _ _ _ _ _ cm2.
19, take any two numbers in 1, 2, 3 and 4 as the sum, and the probability of 5 is _ _ _ _.
There are two boxes. There are three red balls and four white balls in the first box, and four red balls and three white balls in the second box. If you touch a ball from each box, you are more likely to touch the white ball from the _ _ _ _ box.
Third, answer questions.
2 1, and solve the following equation:
( 1)x=
(2)
(3)2x-
(4)
22. Given that the solution of the equation about x is x=2, find the value of the algebraic expression.
23. It is known that the solution of the equation about X is 1 1 times that of the equation about X. Find the value of m and the solutions of these two equations.
24. Equation A (2x+ 1) is known about X = 12x+3b. When a and b are values, the equation (1) has a unique solution; (2) The equation has countless solutions; (3) The equation has no solution.
25. The distance between Station A and bilibili is 3 18km. A local train travels from Station A to bilibili at a speed of 48km/h, and after the local train runs 1 h, an express train travels from bilibili at a speed of 72km/h. How many hours did it take for the local train to meet the express train?
26. There are 45 students in a class, and two students are selected to attend the student congress. The result is that 40 people are in favor of A, 37 people are in favor of B, and those who disagree with A and B are all in favor. What are the numbers of people who agree and disagree?
27. It is known that the hour hand is between 3 o'clock and 4 o'clock. (1) When does the minute hand coincide with the hour hand? (2) When is the minute hand and the hour hand in a straight line?
28. The purchase price of a commodity is 2000 yuan, and the price is 3000 yuan. The store requires a discount at the selling price, and the profit rate is not less than 5%. What's the lowest discount for salespeople to sell this product?
29. In the first half of this year, the monthly precipitation in a certain place was (mm): 1 month:15; February: 20; March: 43; April: 45; May: 32; Jun: 50. Please make fan charts, bar charts and line charts according to the above data, and analyze the information obtained from the charts.
30. There are 1 red, black and white balls in the pocket. If you find 1 ball, put it back in your pocket, then find the second ball, put it back, and then find out the possibility that (1) all three balls are red. (2) The possibility of three colors being the same.
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