Mathematics Residents of a city Domestic water

2m 6 4n=33 (Is the landlord 33?) I can't see clearly...

2m 6 2n=21

Combine the equations to get n=6, m=

y=y=3t-3(2＜t≦4)

y=6t-15(4＜t)

Substituting y=24 into the final function, we get t=

Neither more than tons.

Solution: Derived from the question.

2m+(4-2)x3+(8-4)n=33

2m+(4-2)x3+(6-4)n=21

solution m=yuan).

n=6 (yuan).

1) The functional relation of y with respect to t is:

When t 2, y=mt, bring m= into you get y=when 2< t 4, y=2m+(t-2)x3, bring m= into y=3t-3

When t >4, y=2m+(4-2)x3+(t-4)n, bring m=,n=6 into to obtain y=6t-15

2) Derived from the title.

When t=, 2

y=3t-3

3) If the user's water bill in April is 24 yuan, and a user uses 6 tons of water in February and the water fee is 21 yuan, it can be seen that the user's water consumption in April is t 4

Bring y=24 into y=6t-15, and get t=tons).

A: ......

1) Solution: Let y=kx+b, bring (8,33) and (6,21) in:

8k+b=33 6k+b=21 solution: k=6 b=-15y=6x-15

2) Bring x= into y=6x-15 to get: y=6

The water fee payable is 6 yuan.

3) Bring y=24 into y=6x-15 to get: x=

Tons of water can be used.

<> "Solution: (1) From the meaning of the topic, obtained.

……3 points. , to <>

……4 points. Substitute <> and get <>

The solution is <>

…5 points. >2) When the water consumption is 30 tons, the water fee is: 17 3 + 13 5 = 116 yuan.

9200 2% = 184 yuan.

116 184, Xiao Wang's water consumption in June exceeded 30 tons ......6 points.

Set the water consumption of Xiao Wang's house in June to <>

T, by the title, get <>

…8 points. The solution is <>

…9 points. Xiao Wang's family can use up to 40 tons of water ...... in June10 points.

15,000* yuan, up to 150 yuan water bill.

Assuming that x tons are used, it is obvious that x is greater than 17, and the inherent 17 * 3 + (x-17) * 5 = 150 x = (150-51 + 85) 5 = tons.

Hope it helps.

A family of 3 generally uses about 10 tons of water a month, and the water should be used many times, washing rice--- washing vegetables--- flushing toilets. Mop the floor with water to flush the toilet.

In particular, the water used to wash clothes in a washing machine is often not used properly, and if you wash it by hand, you can save it for flushing the toilet and mopping the floor.

Set to x, then 13*

Solution: x 18 squares.

In the future, you can use this formula to calculate your monthly water consumption by yourself.

What's the question you're asking?

Question 1: 6 2 + 4 4 + 8 4 = 60 (yuan) Question 2: Set the water used in March x cubic meters, then.

y=8(x-10)+ 6 2+4 4=44, solve x=12 (cubic meters) Question 3: If the water used in April is x cubic meters, then the water consumption in May is (20-x) cubic meters, because more is used in May than in April, it is easy to see: x<10<20-x

The water bill for April can be expressed as: 6 2 + (x-6) 4;The water bill for May may be expressed as 6 2 + 4 4 + (20-x The sum of consumption in the month is 6 2 + (x-6) 4 + 6 2 + 4 4 + (20-x-10) 8 = 64

Solution x=8. That is, 8 cubic meters of water was used in April and 12 cubic meters in May.

In order to strengthen citizens' awareness of water conservation and rational use of water resources, a city adopts the means of regulation and control to achieve the purpose of water conservation.

The monthly water consumption is 2 yuan cubic meters.

The part exceeding 6 cubic meters and not exceeding 10 cubic meters is 4 yuan cubic meters.

The part exceeding 10 cubic meters is 8 yuan cubic meters.

Concentrate; Water bills are billed on a monthly basis.

If a household uses 8 cubic meters of water in January, the water charge receivable is 2 times 6 + 4 times (8-6) = 20 yuan.

1) If the resident uses cubic meters of water in February, the water fee should be ——— yuan.

2) If the household uses 12 cubic meters of water in March and April (the water consumption in April exceeds that in March) and pays a total of 26 yuan in water charges, how many cubic meters of water does the user use in March and April?

Question 1: 6 2 + 4 4 + 8 4 = 60 (yuan).

Question 2: Set x cubic meters of water used in March.

y = 8 (x-10) + 6 2 + 4 4 = 44, the solution is x = 12 (cubic meters).

Question 3: If x cubic meters of water are used in April, then the water consumption in May is (20-x) cubic meters, because more water is used in May than in April, and it is easy to see: x<10<20-x

The water bill for April can be expressed as: 6 2 + (x-6) 4;The water bill for May may be expressed as 6 2 + 4 4 + (20-x The sum of consumption in the month is 6 2 + (x-6) 4 + 6 2 + 4 4 + (20-x-10) 8 = 64

Solution x=8. That is, 8 cubic meters of water was used in April and 12 cubic meters in May.

If the water bill is paid Y yuan, and the water consumption of the month is X yuan, then there is.

When x<=m, y=; （1）

x>m,y= （2）

Due to 12 < 22 yuan, it can be seen that Xiaohong's household water is exceeded;

So 22= solves the equation to get m=8

That is: the water standard m set by the city is 8 tons; Xiaohong's home used 4 tons of water in excess of the standard.

In order to advocate residents to save water, tap water for domestic use is charged according to the stepped water price As shown in the figure, the function image between the monthly water (tap water) fee y (yuan) of each household and the amount of water (tap water) used x (tons) According to the information provided in the following figure, answer the following questions: (1) When 17 x 30, find the functional relationship between y and x; (2) When a household uses 15 tons of water in a certain month, ask the household for the water fee for this month; (3) It is known that the water bill of a household last month was 91 yuan, how many tons of water did this household consume last month?