10 application questions for the first year of junior high school!! Urgent!!!!!!

After graduating from college, who knows what to learn in the first year of junior high school, go to the bookstore to flip through the reference books and copy a few.

1.If x individuals process part A, then the number of people processing part B is 85-x. Therefore, according to the meaning of the topic, there is 16x 2=10*(85-x) 3, and the solution is x=25, so 25 people are arranged for part A and 60 people are arranged for part B.

2.Let the speed of the aircraft in the absence of wind be x kilometers per hour, then according to the meaning of the question, there are (2 and 5 6) * (x + 24) = 3 * (x - 24), and the solution is x = 840

So the distance between the two places is 3*(840-24)=2448 km.

1.There are 85 skilled workers in a workshop, each person can process 16 parts A or 10 parts B on average every day, two parts A and three parts B are matched into a set, and how many people can be arranged to process the two parts processed every day when they can just match?

A: B = 2 16:3 10 = 5:12

Per serving: 85 (5+12)=5 (person).

A: 5x5=25 (person).

B: 5x12=60 (person).

2.An airplane flying between two cities, it takes 2 and 5 6 hours to fly downwind, 3 hours to fly upwind, if the wind speed is 24 kilometers per hour, find the distance between the two cities?

24+24) (6 17-1 3) = 2448 (km).

1。Set x people to process type A parts, and arrange 85-x people to process type B parts 16x 2=10 (85-x) 3

48x=20（85-x）x=25

2。Set the distance to x km.

x/（17/6）-24=x/3+24

x/51=48

x=2448

The answer to the first question: If the processing of two parts of A and B is arranged with x, Y people, then 16x parts A and 10y parts B can be produced. According to the title, it can be obtained:

x+y=85

2:3=16x:10y

Solve the equation to get x=25, y=60

The second question assumes that the distance between the two cities is s, and the speed of the aircraft in windless conditions is v kilometers per hour, s (v+24) = 17 6

s/(v-24)=3

Solving the equation yields s=2448

The steps are simple.

The key to doing this kind of question is to figure out the relationship between cars and people, and it is not difficult.

In fact, the time spent is the sum of all the time that takes after one car breaks down and then another car that doesn't break.

The sum is divided into three parts. The time taken for the 1>15 km journey is 15 to 60 hours.

2> The time when the fan and the returning car meet while the fan is walking The time when the car is returning The total distance The total speed.

While the car takes the first group of fans to the hospital, the fans are on foot, and the distance on foot is 5x1 4 (speed x time).

So the total distance is 15-5x1 4 (the distance from the point after the first car reaches the finish line after the fans can't).

Because they are walking in the opposite direction, the time taken is.

3> The third part is the same time as the second part. I can draw a picture, and the car returns to meet the fans, which is the same as picking up the fans and returning to the finish line. So the second and third parts of the time are the same. Also for.

So the sending time should be.

1 4+ minutes < 42 minutes.

So it can be arrived within the stipulated time.

Can be rushed. Because the car from 15 kilometers away to the airport takes 15 60 = 1 4 = 15 minutes, at this time, those walking fans have walked (1 4) * 5 = kilometers, because the car has to turn around, then it can be regarded as the car and the fans to make relative motion, so the time for them to meet (about equal to hours, at this time, the fans have walked 5 * kilometers, there is still (kilometers, after the fans get on the bus, the car will rush to the airport, and it will take about equal to the hour to arrive at the airport, So the whole process takes hours = 39 minutes.

The first group of people need to go from the car breakdown to the airport, 15 60 = 1 4h, the second group of people walk during this period, 5 4km, and then the car turns back to pick up people, and it takes (15-5 4) 65 = 11 52h to meet people, and the car drives to the airport, 11 52h, adding up to 44 minutes.

No. Because at this time, one car is 15 kilometers away from the airport, and the other car has to send the original person to the airport first, and it has walked 45 kilometers three times in total, so it is 45 minutes in total, so it is not in time.

Sorry, not necessarily.

If A sold $x million last year, then B is (150-x).

5x=100

then b last year 150-100=50

This year a b 170-115=55

Solution: If supermarket A sales last year were x, then supermarket B was (150-x) (1+15%) x + (1+10%) (150-x) = 170 solution: x = 100, so supermarket A sales this year is 10,000 yuan.

B supermarket sales this year are 550,000 yuan.

Suppose the turnover of A last year was x0,000, and the turnover of supermarket B was Y, then there is x+y=150

The solution is x=100 y=50

So this year, the turnover of supermarket A is: 1.15 million, and the turnover of supermarket B is: 550,000.

Scheme 1, the average selling price of rice: (100a+100b) (100+100)=(a+b) 2 (yuan kg).

Scheme 2, the average selling price of rice: (100 + 100) (100 a + 100 b) = 2ab (a + b) (yuan kg).

Obviously: a≠b,a, b 0, a +b 2aba+b) = a +b +2ab 4ab

i.e.: (a+b) 2 2ab (a+b).

The average selling price of rice in Option 1 The average selling price of rice in Option 2.

It is more cost-effective to use option 2 to purchase.

I think it should be related to the values of a and b. If a+b 2. Then option 2 is drawn. Otherwise, the plan is drawn

b::100 a+100 b=100*(a+b) ab kg, 1 2 (a+b) ab

The boss uses a method to buy more cost-effective I also saw on the Internet, but I don't know what AB in 100*(a+b) AB means.

It should be a good deal.

1. Team A completes the project alone: 3 (3+2)=3 5 Team B completes the project alone: 2 (3+2)=2 5 Team A completes the project alone

6 3 5 = 10 (days) Team B needs to complete this project alone: 6 2 5 = 15 (days) Answer: Team A and Team B need 10 days and 15 days to complete this project alone.

2. The remuneration due to team A: 20000 3 5 = 12000 (yuan) The remuneration due to team B: 20000 2 5 = 8000 (yuan) Answer: The two teams A and B get 12000 yuan and 8000 yuan respectively.

Solution: (1) It takes 3x days for team A to complete this project alone, and it takes 2x days for team B to complete this work alone. Then:

1/3x＋1/2x＝1/6

The solution of x 5 is tested to be the solution of the original fraction equation.

Therefore, 3x 3 5 15 (days), 2x 2 5 10 (days), that is, it takes 15 days for team A to complete this project alone, and it takes 10 days for team B to complete this work alone (2) Team A's remuneration: 20000 6 15 8000 (yuan) Team B's remuneration: 20000 6 10 12000 (yuan).

A 15 days; B 10 days, A 8000 yuan; B 12,000 yuan.

1. Set: Originally, A made x every day, then B did (x-2), and later, B did (x+2) every day.

Then there is: 624 x=624 (x+2)+2, and the solution is: x=24 (pieces);

So B does 24-2=22 (pcs) per day

2. (1), set A and B to repair x meters and Y meters every day.

Then there is: 12(x+y)=1200, and 8x+18y=1200;

Solution: x=60, y=40;

A and B each need 1200 60 = 20 (days), 1200 40 = 30 (days) (2), set B construction for z days.

z+2*(1200-40z) 60<=35 solution: z>=15

A: Engineering team B will work for at least 15 days.

3. [Formula: add up and subtract, add left and subtract right] easy to obtain: y=-2(x+3)-4=-2x-7

1: If A does x per day, then B will do x-2 per day, and B will do x+2 per day after improvement. Since A and B have 624 pieces left, B has done 2 more days than A, that is, when B has 624 pieces left, A has 624-2x (that is, when A has 624 left, B is greater than 624, B has done two more days, and only 624 remains), and then A and B have completed it at the same time, and the equation 624 (x+2)=(624-2x) (x), and the solution is x=24, then B is originally x-2=22

2: (1) Let A complete x meters per day and B complete Y meters every day, then the system of equations 12x+12y=1200, 8x+18y=1200, and the solution is y=40, x=60, and it is calculated that A alone needs 1200 60=20 days, and B alone needs 1200 40=30 days.

2: (2) Let A complete x days and B need to complete y days to obtain the system of equations 2x+y=35, 60x+40y=1200, and the solution is y=15, x=10. Since the cost of B is less than that of A, if the total cost does not exceed 35, B should be constructed for at least 15 days.

3: Shift 3 units to the left, y=-2(x+3); Translate 4 units downward, i.e., y+4=-2(x+3), to get y=-2x-10. Translation along the x-axis is the change of x, and translation along the y-axis is the change of y.

To the left and down is the corresponding x and y plus, and to the right and up is the corresponding x and y minus.

Solution: If A originally made x per day, then B used to do (x-2) per day, and then (x+2) per day.

Then there is: 624 x=624 (x+2)+2, and the solution is: x=24 (pieces);

B does 24-2=22 (pcs) per day

Solution: Let A take x days and B take y days.

1÷（1/x+1/y)=12

8/x+18/y=1

Solution: x=20

y=30

Answer to question 3: The analytic formula of the function is y=—2x+2