Math Problems in Buying and Selling?Math Problem Problems?

I don't know if Brother Ren will use equations. Here's what you mean by your approach:

Think of three discs as one portion, so there are: 16 3 (the cost of one portion) because 4 discs of 21 yuan is twice as much as 3 discs of 16 yuan, so it is two copies, 2 4 21 (in fact, 21 4 is the cost of one portion, 2 is the cost of two copies).

1+20%) means cost + profit = selling price.

I didn't understand the second question too much, so let's do it with equations, it's relatively simple.

Solution: If the purchase price of the fat boss is (9 10) a, then the purchase price of the thin boss is a and because of the selling price - cost (purchase price) = profit.

Profit Cost (purchase price) = profit %.

So the selling price of the skinny boss is: A+15%A

The selling price of the fat boss is: (9 10) A + 20% (9 10) A Because the selling price of the thin boss is more expensive than the fat boss, so: [A + 15% A] - [9 10) A + 20% (9 10) A] =

The solution is a=160

So (9 10) a = 144

Is it true that thin people are mean?

1) If the number of audio tapes purchased at a price of 16 yuan for every 3 discs is 1, the number of cassettes purchased at a price of 21 yuan for every 4 discs is 2, and the total purchase price is 16 3 + 21 4x2, and the total number of audio tapes purchased is 3;20% profit, the total selling price is (16 3+21 4x2) (1+20%);

For every 3 disks of K yuan, the total selling price is 3 3 k

So k is :(16 3+21 4x2) (1+20%)=19 (yuan).

2) Let the purchase price of the thin boss be 1, the purchase price of the fat boss is 1 10 lower than that of the thin boss, and the purchase price of the fat boss is 1 1 10;

The price of the Skinny Boss is 15% of the profit, and the price of the Skinny Boss is 1 (1+15%);

The fat boss is priced to get 20% of the profit, and the fat boss is priced at (1 1 10)x(1+20%);

The price of a skinny boss is more expensive than that of a fat boss is [1 (1+15%) 1 1 10) (1+20%)].

The purchase price of the skinny boss is: yuan).

The purchase price of the fat boss is 160 (1 1 10) 144 yuan.

The purchase price of the skinny boss is: yuan).

The purchase price of the fat boss is: 160x(1-1 10)=144 (yuan).

Define the range of values for the domain that is the independent variable x. Here x needs to satisfy both the true number of LNU is greater than 0 and the angular sine value of arcsinu is between -1 and 1, so x -1>0 and -1 x -2 1, respectively, to solve x (-1) (1, + and x [-root number 3, -1] [1, root number 3], because to satisfy the two value ranges at the same time, so take the intersection, and finally obtain x [-root number 3, -1) (1, root number 3].

f(x) = 2 * sinx + 2 * cosx = 2 * 2 2 * sinx + 2 2 * cosx] = 2 * cos(4) *sinx + sin(4) *cosx] Note: sin( 4) = cos( 4) = 2 2

2 * sin(x + 4) Note: The two corners and the formula: sin( += sin *cos +cos *sin

Doing this, we know that sin(x+ 4) is a sinusoidal function and its maximum value is 1. So, the maximum value of f(x) is 2.

Obviously, in order for f(x) to be maximized, there must be:

First of all, I want to know what math problem you are going to ask.

First question; Yuan per kilometer.

The second question; 1 11 liters per kilometer.

The first question can be directly divided by the total ** by the total distance.

The second question is to calculate how many liters of oil were added, and then divide the total amount of oil by the distance.

(1) Yuan km.

2) 1 11 liters.

Problem solving process.

400*x 200,x yuan, cost yuan per kilometer.

y 1 11 liters, 1 11 liters of oil per kilometer.

Solution: Problem 1: 200 400 yuan).

A: This car costs yuan per kilometer.

Problem 2: 200 liters).

A: This car needs liters of petrol per kilometer to run.

Note: I don't know if the source of the question comes from, from the current situation, the content of the question stem does not conform to the logic of reality).

200 400 liters of fuel consumption per kilometer.

The cost per kilometer is yuan.

Division issues.

35 Therefore a is to be multiplied by a which is equal to b

Solution: Set the original undiscounted commodity is x yuan, and the eight-fold discount is yuan, according to the title

x=1500 (yuan).

Answer: The original undiscounted product is 1500 yuan.

Set the original price is x yuan, and after 20% off, it is by the title.

x x 1500 answers.

The underpayment of 300 yuan is 2% off.

It turned out that this product was not discounted, and it was 300 yuan.

Let the original product ** be x

then x - = 300

Solve equation x=1500

Question 1: If the first batch of tapes purchased is 3x disks, the second batch is 6x disks, and 6x is divisible by 4, then the common money for buying tapes is q=16x+21*6x 4, then the profit is 20%, then the total sale, then there is the following formula:

k*(x+2x)=, so that you can solve it.

Question 2: The purchase price of the fat boss is, then the search boss is x, then the fat boss and the fat boss are priced respectively, and there is.

can be solved.