The first one dimensional inequality group application problem, urgent

The title is flawed. The price of the biscuit seems to be an integer, we wrote about it.

Solution: Set biscuits x yuan, milk y yuan, according to the title:

90%x+y+

The price of biscuits is an integer, and ten yuan is more than enough to buy a box of biscuits, when x=9, y=when x=8, y=2

When x=7, y=

Another ten yuan is more than enough to buy a box of biscuits, but it is not enough to buy another bag of milk.

Only x=9,y=

A: Biscuits are 9 yuan, milk yuan.

I'll only do starvation with binary one-time inequalities.

The price of biscuits is $x, and the price of milk is $y.

x<=10 and is a positive integer.

x+y>10 gives y>10-x

9x+10y=92

9x+10(10-x)<92

x>8 When x=9, y=eligible.

When x=10, y=eligible, biscuit 9 yuan, milk yuan.

or $10 for biscuits, $10 for milk.

Solution: Set the biscuit x yuan, then the milk (yuan.

x+>10

Solution x>8

x<10

So x=9,

One element inequality is done, and if it is impossible, 2 unknowns must be set.

Solution: Set the biscuits to x and the milk to y.

90%x+y+ can't remember right now. This question.

Solution: Set the biscuits to x and the milk to y.

90%x+y+

There are x rooms on the first floor and y rooms on the second floor.

Then: 4x<48, 5x>48

12

The number of people who have been transferred to service positions is x.

30×1000×(1+20%)≤30×(1+30%)]1000-x)+24x≤33150+24x

Obtained by 36000 39000-15x:

x 200 is obtained from 39000-15x 33150 + 24x

x 150 so 150 x 200

Therefore, the minimum number of people who will be adjusted to service posts is 150 and the maximum number is 200.

0 (20-2x+1) 2 8 (the side against the wall is greater than 0 or less than or equal to 8) 0 21-2x 16

21＜-2x≤-5

5/2≤x＜19/2

Solution: According to the question: x+(x-1)+8 20

2x+7≤20

The value range of 2x 13x x is x meters.

It was still Xiao Ming who won.

When the time taken by the two is the same, Xiao Ming is 100 meters, and Xiao Gang is 97 meters.

Therefore, Xiao Gang's speed is 97% of Xiao Ming's

When Xiao Ming ran 103 meters, Xiao Gang ran meters.

It's still not enough.

Blame me for the wrong table.

Set up x buildings. Get the equation.

560x 14000 (1-20% difference).

Gotta laugh and defeat tremble x 20

A maximum of 20 residential buildings can be built.

Because the area of green grassland in the community shall not be less than 20% of the area of the community, the area of green grassland is set up to be equal to 2,800 square meters of Chengsun Chunyi Sun Kaiying in the community. 14000 minus 2800 equals 11200. Untie.

There are buildings. 560 x 11200 x 11200 560 x 20 So at least 20 buildings are needed.

It is known that the garment factory has 70 meters of A fabric and 52 meters of B fabric, and now plans to produce a total of 80 sets of M and N models of fashion from these two fabrics. It is known that to make a set of M model fashion needs to use A kind of fabric rice, B kind of cloth rice, and you can make a profit of 45 yuan; To make a set of N model fashion, you need to use A kind of fabric rice, B kind of cloth rice, and you can get a profit of 50 yuan. If the number of fashion sets produced with n-type numbers is x, the total profit from the production of these two models of fashion from this batch of fabrics is $y.

1) Find the functional relationship between y (yuan) and x (set), and find the value range from the variable x;

2) In the production of this batch of fashion, when the number of sets of N models of fashion is produced, the garment factory will make the most profit? What is the maximum profit?

Analysis: The two unequal relationships in this question are: the total production of M and N models of clothing requires a kind of fabric not more than 70 meters; The total amount of B fabric required for the production of M and N models of clothing shall not exceed 52 meters.

Solution: (1), i.e

According to the title. Solution, get 40 x 44

x is an integer, and the value range of the independent variable x is 40, 41, 42, 43, 44

The starting price of a taxi in a city is 7 yuan, and the starting distance is 3km, (that is, the starting distance is within 3km and you need to pay 7 yuan,) more than 3km, and each additional 1km increases the fare yuan, (less than 1km is priced according to 1km) Now someone takes this kind of taxi from A to B, and pays no more than that, asking how much is the distance from A to B?