Calculate the following questions in a hurry, calculate the following questions

As shown in Figure 1, the axial cross-section schematic diagram of two cylindrical water tanks of A and B, the initial water depth of A tank is 12 decimeters, and a cylindrical iron block is placed in the middle of tank B. Water is injected into tank B at a constant speed from tank A, and all the water in tank A is injected into tank B after 6 minutes, and the line figure 2 represents the change of water depth in tank B. Based on the question and the information provided by the line chart, answer the following questions:

1. If the bottom area of the B groove is 15 square decimeters, and the thick wall is not counted, the volume of the iron block in the B groove is calculated;

2. If the volume of the iron block in the B groove is 42 cubic decimeters, what is the bottom area of the A groove? Thick walls are not counted.

1. A injects water per minute: 4 15 2 = 30 cubic decimeters, then the water volume injected in the first 4 minutes of A: 30 4 = 120 cubic decimeters, and the water surface rises by 14-2=12 decimeters.

Iron block bottom area: (15 12-120) 10 = 6 Iron block volume: 6 14 = 84 cubic decimeters.

2. Set the area of B bottom x

The volume of iron in unimmersed water: 42 14 12 = 36 cubic decimeters 4 minutes ago, A injected B with the amount of water: 12x-36

After 2 minutes, A injects B with 4x volume

12x-36=2*4x

The solution is x=9, that is, the amount of water injected by A into B is: 12 * 9-36 + 4 * 9 = 108 cubic decimeters, and the bottom area of A: 108 12 = 9 square decimeters.

Solution:1（2x+y-5z)(2x+y+5z)=(2x+y)^2-(5z)^2=4x^2+y^2+4xy-25z^2

4y^2-36)^2-(4y^2-1)^2=(4y^2-36+4y^2-1)(4y^2-36-4y^2+1)

8y^2-37)(-35)=1295-280y^23.(1/2x-1/3y)(1/2x+1/3y)(1/4x^2+1/9y^2)

1/4x^2-1/9y^2)(1/4x^2+1/9y^2)=1/16x^4-1/81y^4

The main thing is to apply the squared difference formula.

Isn't that just a matter of getting around!!

The intersection of 2 and z=0 is the intersection of 2 and . is x-y+1=0

The normal vector of 1 is (1,1,1), just take a random point on x-y+1=0, for example, (0,1,1), x-0+y-1+z-1=0 is the normal of (0,1,1). Then the plane passes x-y+1=0 and x+y+z=2 to obtain the result.

Such as the slippery let the virtual picture answer the mountain.

The whitehead scratching is shorter, and the hairpin is overwhelming.

I express it in 10,000 yuan. The interest income of 50,000 yuan from treasury bonds is not taxed and reduced; The tax payable on foreign non-public welfare donations of 10,000 yuan shall be increased; The original value of a fixed asset is 60,000 yuan, the tax law stipulates that it is the average life method, the depreciation period is 6 years, the annual depreciation is 10,000 yuan, and the depreciation period of enterprise accounting is 3 years, the annual depreciation is 20,000 yuan, and the increase is 10,000 yuan.

Annual taxable income = 500-50 + 10 + 1 = 4.61 million income tax payable = 461 * 25% = 10,000.

Income tax payable in December = 10,000 yuan.