A primary one point application problem, a primary two point application problem, solved

Let the speed of the ship be x kilometers per hour, the speed of the current shall be y kilometers per hour, and the distance between piers A and B shall be = d kilometers.

Because when going downstream, the velocity is x+y, when going against the current, the velocity is x-y, and when the wooden raft drifts down from place A to place B, the velocity is y, then (x+y)*2=(x-y)*3=d

Yes. x+y）*2=(x-y)*3

Get x=5y substitution (x-y)*3=d

d y=12

It takes 12 hours for the raft to drift down from A to B.

Solution: Let the speed of the ship x, the speed of the current y, and the time it takes for the wooden sign to reach B from the drift of A to B.

2(x+y)=3(x-y) x=5y

2(x+y)=zy launched z=12

Suppose the distance between the two places is 1

Then the water velocity is (1 2-1 3) 2=1 12

So wooden drifting time = 1 (1 12) = 12

2 (v ship + v water) = s

3 (v ship - v water) = s

v water st=s v water = 12 5 = hours.

Solution: Set the city's residential water ** per cubic meter x yuan this year, then the ** per cubic meter of residential water in December last year was 3 x 4 yuan, get: 30 x-15 (3x 4) = 5, the solution x 2, the test answer.

Let the farmer's harvest be x, then the harvester's is 150x, and according to the question, 10 (150x) + 1 = 10 (100x) is solved to get x = 1 30

So the harvester reaps for.

Suppose a farmer harvests x hectares per hour, and a harvester harvests 150x hectares per hour. Then: 10 150x

1=10/100x。Since x > 0, then both sides of the equation are multiplied by x, giving x=1 30. Harvester per hour....=1/30*150=5

Assuming the efficiency of the harvester x (hectare hours), the farmer's efficiency is x 150 (hectare hours).

10 (100 times x 150) 10 x 1

Find x 5

In fact, as soon as you analyze it, you can know the selection of team A, I will use the idea of junior high school to do it for you, you can see if you understand.

Solution: Let team B's work efficiency be x (i.e., the amount of work completed per day is x).

From the question "Team B completes the project twice as long as Team A", it can be seen that Team A's work efficiency is twice that of Team B, so Team A's work efficiency is 2x

So the whole quantity is (2x+x)x 20=60x

If team A needs 60x 2x = 30 days for construction alone, a total of 1000x30 = 30000 yuan needs to be paid.

If team B needs 60x x = 60 days for construction alone, a total of 550x60 = 33,000 yuan needs to be paid.

Therefore, from the perspective of saving money, the company should choose team A and should pay 30,000 yuan for the engineering team.

Got it?

The flow rate of water is x kilometers. Solution: 5(14-x)=4(14+x) 70-5x=56+4x

9x=14x=14 9 km.

Check: 5(14-14 9)=4(14+14 9) 70-70 9=56+56 9

Multiply both sides by 9 to get: 630-70=504+56 560=560 The two sides are equal.

A: The flow rate of water is 14 9 km.

Average speed = total distance and total time.

The total distance is 2s

Ascent time = s x

Descent time = s y

So velocity = 2s (s y + s x).

After simplification, it is =2xy (x+y).

The time taken to ascend the mountain is s x, the time taken to descend the mountain is s y, and the total distance up and down the mountain is 2s, which is simplified to 2xy (x+y) by dividing the total route by the total time. Thank you!!

Solution: Let the speed of the passenger car on the ordinary highway be x kilometers per hour. Note: The unit of velocity is not clearly stated in the title. Therefore, it is not easy to determine the unit of time, tentatively x kilometers of hours.

Equation 2 [480 (x+45)]=600 x

The solution is x=75 The time it takes for a passenger car to travel from A to B on the highway is 480 (75+45)=4 (hours).

Solution: A needs x days, then B needs days, then A completes 1x per day, and B completes 1 per day;

then there is 1 (1 x+1

Solve x=i.e., it takes days for A to complete the task, and days for B.

Xiaoli speed x

Xiaojie x+4 time t(x+4)*t=240

x*t=160

Subtracting the two formulas yields t=20

Bringing t into any equation yields x=8

So Xiaoli can do 8 dishes per minute.