Math problems, open again !! A math problem !!

A cylinder, a cuboid, and a cone, and their base area and volume are equal, respectively, then the (cone) body is the highest, and the (cylinder) body and the (cuboid) body are equal in height.

When a cube of iron is cut into two identical cubes, the surface area is increased by 8 square decimeters, and the original surface area of the cube is (48) square decimeters.

A conical container, 15 cm high, filled with water, if all the water is poured into a cylindrical container of the same height as the bottom, the water surface of the cylindrical container is (5) cm high. Question added:

1. The cuboid is the highest, and the height of the cylinder and the cone are equal.

2. The surface area of the cube is 24m 2

3. The water surface of the cylinder is 5cm high

The cone is the highest, and the height of the cuboid and the cylinder is equal.

24 square decimeters.

5 cm. Cylindrical body, 3 cm high, square centimeter of side area, cubic centimeter of volume.

1 The cone is the highest, and the cylinder and the cuboid are equal in height.

2 A surface area: 8 2 = 4 (square decimeters) surface area; 4 6 = 24 (square decimeters).

3 15 one-third = 5 (cm).

If the first purchase of x pieces, then the second purchase of 2x pieces, then the first purchase price is 1000 x, and the second purchase price is (1000 x + 2x=2500, that is, 500 = 5x, x = 100, then the second purchase of 200 pieces.

Or think like this, the second time I bought the amount of stationery purchased is 2 times the first purchase, the first time I used 1000 yuan, if the price does not rise, the second time will only use 2000 yuan, and the second time I used 2500 yuan, so many out of 500 for the price increase, each price increase, then a total of 500 pieces will be sold out of 500 yuan more.

Solution: The first time into x pieces, the second time 2x pieces.

Finishing: 1250 x-1000 x=

The solution is x=100 and 2x=200

Answer: The second time to enter 200 pieces of stationery.

There are so many superfluous conditions in it. (2500 x) is the unit price of the second entry; Subtracting the rising yuan, it is equal to the unit price of the first entry (1000 x).

Give points, adopt, or I'm too sorry for me.

Solution: Set the number of stationery purchased by the boss for the first time is x, and the unit price is yxy=1000

2x*（y+

Solve the equation to obtain: x=100y=10

A: Q: I bought 200 pieces of stationery for the second time.

Set up the second purchase of stationery x pieces.

then purchase x 2 pieces for the first time.

The first bid price is 1000 (x 2) = 2000 x the second bid price is 2500 x

It is known that (2500 x) - (2000 x) = x = 200

Suppose the first ** is n, then there is none.

2*（1000/n）=2500/(

n=102500 10=250 pieces.

1. Connect to BG

PQ bisects AB vertically

AG=GB, the triangle AGH is folded from the triangle ABH.

ag=ab=20

ag=ab=gb=20 i.e. equilateral triangle agb angle gab=60°

Angle hab = 30°

RT triangle ABH.

Angle hab = 30° angle b = 90°

ah=2hb

From the Pythagorean theorem, ab 2 + bh 2 = ah 2 i.e. ab 2 + bh 2 = 2bh 2

The solution is ah=(40 3) 3cm

2. Folding.

ed=be and set ce=x

In the RT triangle ced.

ce^2+cd^2=de^2

i.e. x 2 + 20 2 = (25-x) 2

The solution is x=be=de=

Connect bfde=be, def=be, ef=ef The triangle def is all equal to the triangle bef

bf = de angle def = angle bef angle bef = angle dfe

Angular def = angular DFE

df=dedf=de=bf

bf = de, cd = ab, angle c = angle b = 90° triangle ced is equal to triangle afb

af=ce=

Make FH parallel to AB and cross BC to H

bh=af=

EH = 16 in the RT triangle FEH.

fh^2+eh^2=ef^2

20^2+16^2=ef^2

ef=4√41cm

Question 1: Prov: 16m +48m, m is a non-zero real number, the value of 16m +48m is always greater than 0, and the value is greater than 0, and there are always two different real roots.

Question 2: s abc 16

From the root finding formula: x = 3m or -2m

The m value is -4 under the cube root

Solution: There are x yakshas, y nezha. It consists of eight arms and one number Yaksha, and three heads and six arms are Nezha.

Thirty-six heads were dispatched in unison, and one hundred and eighteen hands grabbed each other in disorder.

So 8x+6y=108 x+3y=36

Get x=6 y=10

10 Nezha 8 Yakshas!

There are x yakshas, y nezha.

Then the yaksha has a head 1x and an arm 8x

And Nezha has a head 3Y and an arm 6Y

Because of thirty-six heads.

x 3y=36

Because of one hundred and eight hands.

Therefore 8x 6y = 108

2 after and minus.

Finally, substitute to find the difference.

10 Nezha 8 Yakshas!

1.Let the speed of the ship be x, the speed of the water (x+3) and the speed of the water (x-3), and the equation is listed according to the equal distance.

2(x+3)=

x=272.Let the purchase price of each unit be x, and the list price is the selling price.

x=2500

3.Set a total of water x

va=x/3

vb=x/4

vc=x/6

Water - A Inlet Water) (BC Pipe Speed) = Time (

1.If the speed of the ship is x, then the speed of the ship is (x+3), the speed against the water is (x-3), and the distance between the two piers is 2x(x+3).

Because the distance between the two piers remains the same.

There is 2x(x+3)=

The solution is x=27 and says that the distance between the two piers is 60km2Let the purchase price of each unit be x, and the list price is (1+ the selling price is (1+ that is, so there is a solution x=2500

So the profit margin is 300 divided by 2500, and the result is 12%3If the volume of the swimming pool is considered as 1, the flow rate of a is 1 3 b, the flow rate of 1 4 c is 1 6

Assuming that the required time is x hours, according to the title, there are (1 3 x 1 2) + (1 4 - 1 6) x = 1 2

Solution x=4 So you can fill half a pool of water in 4 hours Give it to me Thank you