When the coefficient of A.x is 0 b and the degree of x is 0 C.-2, the first D.-2 is algebraic.

2. The following items with different formats are ()

A. the sum of the squares of xy, x, y, B. 1/3ab, c and cab.

C.- 1/2 and 0d 1/3 xy and -xy

3. The side length of a square is xcm. As the side length increases, the area of acm () increases.

A.a's square cm's square B.(x's square +a's square) cm's square.

C the square of (x+a) is the square of d [the square of (x+a)-the square of x] is the square of cm.

4. Let -(m-2n)+(m squared +2n squared) be ().

A.-m-2n+m's square +2n's square B.-m+2n-m's square -2n's square

C.-m+2n+m's square +2n's square D.-m+2n-m's square +2n's square

5. When x is equal to 1 and-1 respectively, the algebraic expression X +2x squared +5 has two values ().

A. reciprocal B. reciprocal C. different symbols D. equal

1, 1500 A group of seventh-grade students in a school went on a spring outing, using 32 cars. Among them, "Big Golden Dragon" coach can take 50 students per car, and "Little Golden Dragon" coach can take 40 students per car. How many "Big Jinlong" cars and "Little Jinlong" cars will be sent?

2. Team A has 50 vehicles and Team B has 4 1 vehicle. If team B has more vehicles than team A 1, how many vehicles should team A transfer to team B?

3. Xiao Zhao went to the store to buy exercise books. When he came back, he asked his classmates, "The shopkeeper told me that if I bought more, I would get a 20% discount. I bought 20 copies, and the result was cheaper 1.60 yuan. " What is the original price of this exercise book?

4. The distance between Party A and Party B is 180km. One person travels every hour from Party A by bike 15km, and the other person travels from Party B by motorcycle. As we all know, the speed of a motorcycle is three times that of a bicycle. If two people travel in the same direction, ride a bike first and start for 2 hours. How long will it take for the motorcycle to catch up with the bike?

5. The unit price of methyl sugar is per kilogram of 20 yuan, and the unit price of ethyl sugar is per kilogram 15 yuan. If you want to prepare 200 kilograms of mixed candy with the unit price of 18 yuan per kilogram, and keep the total revenue of selling the two kinds of candy unchanged, how many kilograms do you need for each of the two kinds of candy?

5. Cars A and B, A goes from place A to place B, and B goes from place B to place A, walking in opposite directions at the same time, and the two cars meet at 1 hour 30; After the encounter, it will take 2 hours for a car to arrive at B, and it will take 1 hour for b car to arrive at A. If the distance between A and B is 2 10 km, the speed of A and B cars is V A = _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

6. A said to B: If I were your age now, your age at that time was half my age now; When you reach my present age, the sum of our ages will be 63. Then A is now _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

7.a is a two-digit number and B is a single digit. If they are combined into a three-digit number, so that the highest bit of the three-digit number is B, then the algebraic expression of the three-digit number is _ _ _ _ _ _ _ _.

Second, multiple-choice questions (3 points for each question, ***24 points)

5. A factory to assess workers, a *** 10 task; If you complete one item within the specified time, you will get 10, half will get 5 points, and if you can't do one item at all, you will get 2 points. If the worker gets 78 points after the examination, he gets 10, and the items you can't do are () in turn.

(a) 6,4, 1 (b) 7,2, 1 (c) 8,1,2 (d) are all wrong.

6. Mix 30% and 60% salt solution to make 40% salt solution 100g. How many grams of salt solution do you need? Suppose you need x grams of 30% saline and y grams of 60% saline. According to the meaning of the question, the equation can be listed as ().

7. It is known that x and y are opposite numbers and (x+y+4) (x-y) = 4, then the values of x and y are () respectively.

(A) (B) (C) (D)

8. Assume that the solution of the equation is positive and the range of a is ().

(a) A < 4 (b) A < 6 (c) 4 < A < 6 (d) does not exist.

Four, solve the application problems of equations (1 ~ 7 questions each 5 points, 8 questions 3 points, ***38 points)

1. There are five-year and three-year treasury bonds. Party A buys five-year treasury bonds 100 yuan, three-year 200 yuan, with an average annual interest of 10%, and Party B buys five-year 300 yuan, with an average annual interest of 1 1%. Seek five.

2. Someone rode a bicycle downhill at a speed of 12km/h, and then leveled the road to B at a speed of 9km/h, which took 55 minutes. When he came back, he crossed the flat road at a speed of 8km/h, and then went uphill at a speed of 4 km/h. It took 1 h to get the distance between A and B.

3. There are two rectangles. The ratio of the length and width of the first rectangle to that of the second rectangle is 5: 4: 3: 2. The circumference of the first rectangle is 72 cm longer than that of the second rectangle. Find the area of these two rectangles.

4. The reservoir has a certain amount of water inflow. According to the current discharge, the water in the reservoir can be used for 80 days, but recently, due to sunlight, the inflow has decreased by 20%. According to the current emissions, water can only be used for 60 days. What are the current inflow and discharge?

5. Party A and Party B walk in opposite directions from two places 28 kilometers apart at the same time and meet at 3 hours and 30 minutes; If B leaves 2 hours before A leaves, so that A meets B after 2 hours and 45 minutes, what are the speeds of A and B respectively?

6. A worker received the task of processing a batch of parts and finished it within a limited time. He calculated that if he makes 10 parts per hour, he can overfulfil the task by three, and if he makes 1 1 parts per hour, he can finish it 1 hour in advance. How many parts has he machined? How many hours is the deadline?

7. Three students bought stationery. A bought four pencils, a ruler and ten exercise books, and paid 1.69 yuan. B bought three pencils, a ruler and seven exercise books, which were handed in 1.26 yuan. C bought a pencil, a ruler and an exercise book. How much did it cost?

8. A shopping mall plans to allocate 90,000 yuan to buy 50 TV sets from manufacturers. It is known that this factory produces three different models of TV sets, the ex-factory price is 1500 yuan, 2 1000 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 a set of A, B and C TVs, it can make profits respectively 150 yuan, 200 yuan and 250 yuan. Please confirm which purchasing scheme should be chosen to maximize the profit of the mall.

(3) If the mall is going to buy 50 TV sets of three different models at the same time with 90,000 yuan, please design the scheme.