1. Be patient and make a decision! (4 points for each small question, ***32 points)
1. Among the equations ①, ②, ③, ④, ⑤, ⑤, there is a linear equation.
2. When =, the values of formula and are opposite to each other.
3. If known, then =.
4. Write a one-dimensional linear equation so that its solution is -23, the unknown coefficient is a positive integer, and the equation is.
If a store sells a commodity at 10% of the marked price, it can still get a profit rate of 20%. If the purchase price of the commodity is 30 yuan per piece, the price is RMB per piece.
6. A Chinese herbal medicine contains four herbal components A, B, C and D, and the mass ratio of these four herbal components is 0.7∶ 1∶2∶4.7. Now we need to prepare 1400g of this Chinese medicine. How many grams do these four herbs need respectively? Let each copy be grams. According to the meaning of the question, you get.
7. There is a column number, which is arranged according to a certain rule:-1, 2, -4, 8,-16, 32, -64, 128, …, and the sum of some adjacent three numbers is 384, which are respectively.
8. For a project, it takes 20 days for Party A to complete it alone, and 25 days for Party B to complete it alone. Then Party A will do it for 2 days first, and the remaining two parties will do it for a few days.
Choose carefully, and you will know gold with your eyes! (3 points for each small question, ***24 points)
1. If it is a linear equation, it is equal to ().
(A) 1 (B)2 (C) 1 or 2 (D) any number
2. Equations 3 +5=0 and 3 +3 = 1 have the same solution, then = ().
Items 1 to 2
3. When solving the equation, it is correct to remove the denominator ().
(A) (B)
(C) (D)
4. Known, it is equal to ().
(A) (B) (C) (D)
5. It is a two-digit number, a three-digit number, and the expression of five digits is ().
(A) (B) (C) (D)
6. A test paper consists of 26 questions. If you answer a question correctly, you will get 8 points, and if you answer a question incorrectly, you will get 5 points. Today, a candidate did all 26 questions, but the total score was zero. The question he did correctly was ().
(A) 10 lane (B) 15 lane (C)20 lane (D)8 lane.
7. An individual vendor sells two coats at the same time, and the price is 135 yuan. If calculated by cost, one of them will make a profit of 25% and the other will lose 25%. In this transaction, he ().
(a) Don't make a loss; (b) Make a loss in 9 yuan; (c) Make a loss 18 yuan; (d) Make a profit 18 yuan.
8. A passenger with 30 kilograms of luggage flew from Nanjing Lukou International Airport to Tianjin. According to the civil aviation regulations, the passenger can carry up to 20 kilograms of luggage for free, and the overweight part can buy baggage tickets at 65438+ 0.5% of the ticket price per kilogram. Now that the passenger has bought the baggage ticket for 1.20 yuan, his ticket price should be ().
(A) 1000 yuan (B)800 yuan (C)600 yuan (D)400 yuan.
3. Do it with your heart and you will succeed immediately! (This big topic ***64 points)
1.(8 points) Solve the equation:.
2.( 10) If the solution of the equation is the same as that of the equation, find the value of the equation.
3.( 10) Spread your imaginary wings, try to guess what kind of practical problems may be from the equation, write them down and answer them.
4.( 1 1 min) Party A and Party B ride bicycles in opposite directions from two places 65km apart. The speed of Party A is 17.5km/h, and the speed of Party B is15 km/h. After several hours, the distance between them is 32.5km?
5.( 12 points) The number matrix on the right is made up of some odd numbers. 13579
(1) What is the relationship between the four numbers in the box on the right? (The first number in the first line of the box is113151719.
For) ..............
(2) If the sum of the four numbers framed in this way is 200, find these four numbers .9193959799.
(3) Is the sum of these four numbers 420? Why?
6.( 13) The mall plans to allocate 90,000 yuan to buy 50 TV sets from the manufacturers. It is known that this manufacturer produces three different models of TV sets, and the apparent price is 1500 yuan, 2 100 yuan per set and 2,500 yuan per set.
(1) If the shopping mall buys 50 TV sets of two different models at the same time, and it costs 90,000 yuan, please study the shopping plan of the shopping mall;
(2) If a shopping mall sells Class A TV sets with a profit of 150 yuan, Class B TV sets with a profit of 200 yuan and Class C TV sets with a profit of 250 yuan, which purchase scheme should be chosen to obtain the maximum profit?
Reference answer:
I. 1.2466 2。 -43 19 3. 1 4. etc. 5.40 6.7. 128,
-256,5 12 8. 10
Two. ACCDC
Three. 1. finishing,
Denominator, get,
Remove the brackets,
Move the item, get it,
Merge, acquire,
The coefficient is 1, and it is obtained.
2. Solve the equation and get it.
Substitute into the equation and you will get
,
Solution, so =
3. Omit.
4. There are two situations about this problem:
Situation 1: The first interval is 32.5km.
Suppose an hour later, the distance between them is 32.5 kilometers.
,
Solve.
Case 2: The second time is 32.5km apart.
Suppose an hour later, the distance between them is 32.5 kilometers.
,
Solve.
Answer: 1 hour or 3 hours later, the distance between them is 32.5 kilometers.
5.( 1) Let the first number in the first row be, and the other three numbers be.
(2) According to the meaning of the question,
The solution is =45, so these four numbers are 45, 47, 53 and 55 in turn.
(3) it does not exist.
Because the solution =50 is an even number, it does not exist.
6.( 1) ① Buy a TV set of B (50-).
1500 +2 100(50- )=90000.
Solve this equation and get =25.
Then 50-= 25.
Therefore, the first purchase plan is to buy 25 A-type and B-type TVs respectively.
(2) buy a TV set, then buy a C TV set (50-).
1500 +2500(50- )=90000.
Solve this equation and get =35.
Then 50-= 15.
Therefore, the second purchase plan is to buy 35 Class A TVs and 15 Class C TVs.
(3) Set to buy B TV sets, and then buy C TV sets (50-) to get the title.
2 100 +2500(50- )=90000.
Solve this equation and you get =87.5 (irrelevant).
So this scheme is not feasible.
(2) The above-mentioned first scheme can make a profit: 150× 25+200× 25 = 8750 yuan,
The second scheme can be profitable:150× 35+250×15 = 9000 yuan,
Because 8750
This manuscript is suitable for the seventh grade (1 1) level test column of People's Education Press.