Solving applied problems of linear inequalities with one variable A company purchased 40 sets of air conditioners and 60 sets of refrigerators, and allocated them to its two subordinate shopping malls for sale, 70 sets in shopping mall a and 30 sets in shopping mall B. the profits of two kinds of electrical appliances sold by the two shopping malls are as follows: (unit: yuan) Air conditioning refrigerator Department store a 200 170 Shopping mall B 160 150 (1) The company supplies x air-conditioners to a shopping mall. The total profit of the two shopping malls after buying all the electrical appliances is expressed by the algebraic formula of X, and the value range of X is calculated (2) In order to promote the sales, the company decided to give a profit of a yuan to each air conditioner in a shopping mall, but the profit of each air conditioner should not be less than the profit of each refrigerator in a shopping mall?

Solving applied problems of linear inequalities with one variable A company purchased 40 sets of air conditioners and 60 sets of refrigerators, and allocated them to its two subordinate shopping malls for sale, 70 sets in shopping mall a and 30 sets in shopping mall B. the profits of two kinds of electrical appliances sold by the two shopping malls are as follows: (unit: yuan) Air conditioning refrigerator Department store a 200 170 Shopping mall B 160 150 (1) The company supplies x air-conditioners to a shopping mall. The total profit of the two shopping malls after buying all the electrical appliances is expressed by the algebraic formula of X, and the value range of X is calculated (2) In order to promote the sales, the company decided to give a profit of a yuan to each air conditioner in a shopping mall, but the profit of each air conditioner should not be less than the profit of each refrigerator in a shopping mall?

(1) According to the meaning of the title, if you allocate to chain store a (70-x) refrigerators, chain store B (40-x) air conditioners, and chain store B (X-10) refrigerators, then y = 200X + 170 (70-x) + 160 (40-x) + 150 (X-10), that is, y = 20x + 16800

Known equations x + y = 1-A
The solution X of X-Y = 3A + 5 is positive and Y is non negative
(1) Find the value range of a
(2) Simplification │ a + 3 │ + │ A-1 │

x+y=1-a
x-y=3a+5
Add
2x=2a+6
x=a+3y=-2-2a
So a + 3 > 0,
2-2a≥0
So - 3

An engineering team needs to recruit 150 workers of a and B, whose monthly wages are 600 yuan and 1000 yuan respectively. Now, the number of workers of B is not less than twice of that of a, so how many workers of a can be recruited to make the monthly wages at least?

Suppose x workers of type A are recruited, then (150-x) workers of type B are recruited. According to the meaning of the question: 150 − x ≥ 2XX ≥ 0, the solution is: 0 ≤ x ≤ 50, and the monthly wage of workers is y yuan, then y = 600X + 1000 (150-x) = - 400X + 150000 (0 ≤ x ≤ 50). Because k = - 400 ＜ 0, the linear function y decreases with the increase of X, so when x = 50, y has the minimum value y = - 400X + 150000 = - 400 × 50 + 150000 = 1300 A: recruit 50 workers of type A and pay the minimum wage of 130000 yuan

How to calculate the math problem and the formula
The task is to buy 1000 eggs for 10000 yuan. In fact, we only bought 800 eggs for 8000 yuan. What's the total percentage? What's the formula?

I bought 80% of the total
If A1 is the target value and B1 is the actual completion value, enter the formula in C1: "B1 / A1 * 100" or enter the formula in C1: "B1 / A1", and then set the C1 cell format to percentage. If A1 enters 1000 and B1 enters 800, C1 will display "80" or "80%"

The first item is 12345, the last item is 54321, what is 43251? What is the 93rd item?

(1) If ten thousand

X to the 10th power = x times () to the 3rd power = () to the 2nd power

X to the 10th power = x times (x ^ 3) to the 3rd power = (x ^ 5) to the 2nd power

1. The bookshelf has two layers, 173 books in total. After taking 38 books from the first layer, the books on the second layer are 6 times more than those on the first layer. How many books are there on the second layer?
2. The speed of a, B and C is 30 meters. 40 meters. 50 meters per minute respectively. A and B are at point a and C are facing each other at the same time. C meets a 10 minutes after meeting B. how long is the road between a and B?

Let's set the original x copy in the first layer and 173-x copy in the second layer
173-X=2(X-38)+6
X=81
∴173-X=92
Let C meet B in X minutes. According to the distance between a and B when C meets B and C meets a, the sum of their journeys is the distance between a and B
40X+50X=30(X+10)+50(X+10)
X=80
∴90X=7200

The formula of distance from point to surface
For a long time, there was no definite answer
I mean the formula of the distance from point to face in space

Let ax + by + CZ + D = 0
The distance formula from point (x0, Y0, Z0) to surface is
D = - ax0 + by0 + CZ0 + D \ / root (a ^ 2 + B ^ 2 + C ^ 2)
It is similar to the formula of the distance from a point to a straight line. It only relates to space, and it is also a right triangle formed by making a vertical line and a diagonal line of a plane through the point

For the quadratic trinomial X & sup2; - 10x + 36, Xiao Cong made the following conclusion: no matter what real number x takes, its value cannot be equal to 11

Suppose he's right, that's the equation
x²-10x+36=11
The quadratic equation has a solution
Namely
x²-10x+25=0
The discriminant △ = 10 & sup2; - 25 × 4 = 0
That is to say, the equation has two identical roots, x = 5
It is shown that x = 5 makes X & sup2; - 10x + 36 = 11
His statement is wrong

Is DX integral or differential to X in calculus

DX is the derivative of X, not the integral, and the reduction is the derivative