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First of all, 10 tons per month will be paid.

1) If Xiaohua's family pays 17 yuan for water in April, they can get 10 + (17-13) 2 = 12 tons.

His family used 12 tons of water in April.

Set up his house to use x tons of water in April.

x-10)*2+10*

x-10)*2=4

x-10=2

x = 12 tons.

His family used 12 tons of water in April.

2) No more than 15 tons per household, we can first calculate how much money is needed for 100 households, just 10 tons, 100 * 13 = 1300 yuan, 1682-1300 = 382 yuan, and 382 2 = 191 tons.

If each household has a maximum of 15 tons, it is 191 5 = 39 households.

Residents with a monthly water consumption of less than 10 tons may have a maximum of 100-39 = 61 households, let x be the residents with more than 10 tons of water consumption in the month, and the residents with no more than 10 tons are 100-xx*(10*

23x+1300-13x=1682

10x=382

x= 39 households.

Residents of no more than 10 tons are 100-x = 61

1.Set up x tons of water.

2×（x－10）＋

x=122.I don't understand.

1.Solution: Let the radius r of the basketball be x, according to the problem, 3 4 multiplied by x to the third power = 9850

The solution is x=(9850 divided by 3 4 and then divided by the result of the cubic square) (the calculator calculates by itself) Answer: .2.Solution: Let the length of the rectangle be 5x, then the width is 3x, according to the problem, the arithmetic root number 5x multiplied by the arithmetic root number 3x equals the arithmetic root number 68

The solution is x = (5x multiplied by 3x = 68, 15 times x squared = 68, x = 15 68 squared) (the answer is the same as above) 5x = .3x=..

A: ...

Set a formula! v=4/3×πr³

4/3×πr³=9850

Divide it again and you're done!

Set length 5x, width 3x

5x) +3x) = 68) under the root number

That's it! (This question uses the Pythagorean theorem!) ）

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.

The calculation method of levying individual income tax (the threshold is 2,000 yuan), and the calculation method using the excess progressive tax rate is as follows:

Tax paid = monthly taxable income * tax rate Quick deduction.

Taxable income for the whole month = (payable salary four gold) 2000 If the four gold is 0, the taxable income is 4000 2000 2000 tax paid 2000 * 10% 25 (quick deduction) 175 yuan.

The opposite side of a is the opposite side of the cube root number -8 b, the opposite side of the negative root number 2 c is 2 times the root number 2

a+b+c=-1 2+root:2-2 times,root:2==-1,2-root,2-root,2

I really can't see the figure clearly, I can only tell you the number of B to the left of C, and the number of A to the left of C.

Let A get x yuan for completing the work every day, B gets y yuan for completing the work every day, and C gets z yuan for completing the work every day, then 6x+6y=1800 3=600

2y+2z=1800/6=300

5x+5y+5z=1800-900=900, then z=80 y=70 x=30

A worked for 11 days and got 330

B worked for 13 days and got 910

C worked for 7 days and got 560

It's very simple: first calculate that if they have been cooperating to complete the task, it will take 18 days to complete it, and they can get 100 yuan a day, and each person will get 100 3 yuan, which means that 18 days is their task; First, three people complete 18 * (1 3) = 6 days, a total of 6 * 100 = 600 yuan, B and C cooperate to complete 18 * (1 6) = 3 days, a total of 3 * 100 = 300 yuan, and finally three people cooperate to complete 18-6-3 = 9 days, a total of 9 * 100 = 900 yuan, so A gets 600 3 + 900 3 = 500 yuan, B and C each get 600 3 + 300 2 + 900 3 = 650 yuan.

Let the velocity of A be x, the velocity of B be y, and the velocity of C be z, then 6(x+y)=1 3

2(y+z)=1/6

5(x+y+z)=1-1/3-1/6

Solving the system of equations gives x=1 60, y=7 180, z=2 45, then the workload of A is 11x=11 60

B's workload is 13y = 91 180

C's workload is 7z = 14 45

Then A should get a salary of 1800 * 11 60 = 330 yuan.

B's salary is 1800 * 91 180 = 910 yuan.

C's salary is 1800 * 14 45 = 560 yuan.

Three-person cooperation for five days 1-1 3-1 6=1 2 Three-person cooperation for one day 1 2 5=1 10 A and B work efficiency 1 18

The work efficiency of B and C 1 12 A and two B and one C 1 18 + 1 12 = 5 36 The work efficiency of one B 5 36-1 10= 7 180 The work efficiency of A 1 18-7 180 = 3 180 The work efficiency of C 1 12-7 180 = 2 45 The work efficiency ratio of A B C 3:7:8 1800 (3+7+8)=100 yuan A 300 yuan B 700 yuan C 800 yuan.

(1) The total number of 8th grade students in this school x <300

If you buy 60 more sticks, you can wholesale and reach 300 people, so the number of people to buy may be the minimum is 300-60 = 240, and the number of people is between 240 x <300.

2) The price for buying 6 sticks is the same as buying 5 sticks at the retail price, if you buy 60 sticks more, it is the retail price of 50 sticks, and 50 people are less.

It should be 240 + 60 = 300 people.

If you buy 60 sticks (there is a problem here), then you can pay according to the wholesale price, which also costs 120 yuan.

The number of 8th grade students is set to x.

1. If the number of 8th grade students is x, then x is greater than 240 and less than or equal to 300

2 120 x*5=120 (x+60)*6 The solution gives x equal to 300

...You tell me the topic first.

Option 1 is actually a direct equation, and if you insist on the equation, let the profit be x because < 30

So x=52800 (yuan).

Scheme 2: The first step is the same as the direct formula, if you insist on the equation, set the profit to yy=3750+7500=78750 (yuan), and the second step is to the equation.

Because < 30, > 30, the scheme exists.

Let the roughing quantity be a and the finishing quantity be b, and the column equation is:

a+b=a/8+b/

a=40 (t) b = t).

The profit is 40 * 1000+ yuan).

3) Set x days for finishing and (60-x) days for rough machining.

1) 105 1000 = 105000 (yuan) 2) yuan).

3) Rough machining x days, finishing (60-x) days, profit y, yes.

8x+（60-x）×

So, x=10

y=1000 8x+5000(60-x) yuan).

Plan 1 makes a profit of 105,000 yuan. Plan 2 makes a profit of 157,500 yuan; (Processing tons per day, processing 30 tons in 60 days, making a profit of 150,000 yuan.) A total of 105 tons of processing, 30 tons and 75 tons of direct sales, 75 tons of direct sales profit of 7,500 yuan.

The total profit of processing and direct sales is 150,000 + 7,500 = 157,500 yuan). Plan 3: Profit 205,000; (Rough processing, processing 80 tons of profit 80,000 yuan.) A total of 105 tons have been processed, 80 tons and 25 tons, finishing, processing tons per day, a total of 60 days have been used, 10 days and 50 days, multiplied by 50 = 25 tons just right.

Then the finishing profit is 125,000 yuan. Rough and finishing made a total profit of 205,000 yuan).