100 points for a math problem 100 points for a math problem

Direct deposit, fixed deposit, lump sum deposit and withdrawal for 3 years. For example, 10,000 yuan: 10,000 yuan a year: 10,000

Two years: 10,000

Solution: (1) According to the question.

1000(x+t 8)=500, simplified to 5x2+(8t 80)x+(4t2 64t+280)=0 when the discriminant formula =800 16t2 0, x=8 can be obtained

By 0,t 0,8 x 14, get the inequality group:

To solve the inequality group, 0 t is obtained, and the inequality group has no solution, so the defined domain of the function relation is [0, ].

2) To make x 10, there should be.

Simplify to get t2+4t 5 0

The solution is t 1 or t 5, and t 0 knows t 1 so that the subsidy is at least 1 yuan per kilogram

1000(x+t 8)=500, simplified to 5x2+(8t 80)x+(4t2 64t+280)=0 when the discriminant formula =800 16t2 0, x=8 can be obtained

By 0,t 0,8 x 14, get the inequality group:

To solve the inequality group, 0 t is obtained, and the inequality group has no solution, so the defined domain of the function relation is [0, ].

2) To make x 10, there should be.

Simplify to get t2+4t 5 0

Get t 1 or t 5, from t 0 to t 1

**The subsidy is at least $1 per kilogram.

Solution: (1) According to the question.

1000(x+t 8)=500, simplified to 5x2+(8t 80)x+(4t2 64t+280)=0 when the discriminant formula =800 16t2 0, x=8 can be obtained

By 0,t 0,8 x 14, get the inequality group:

To solve the inequality group, 0 t is obtained, and the inequality group has no solution, so the defined domain of the function relation is [0, ].

2) To make x 10, there should be.

Simplify to get t2+4t 5 0

The solution is t 1 or t 5, and t 0 knows t 1 so that the subsidy is at least 1 yuan per kilogram

Direct deposit, fixed deposit, lump sum deposit and withdrawal for 3 years. For example, 10,000 yuan: 10,000 yuan a year: 10,000

Two years: 10,000

A: As above (omitted).

1000(x+t 8)=500, simplified to 5x2+(8t 80)x+(4t2 64t+280)=0 when the discriminant formula =800 16t2 0, x=8 can be obtained

By 0,t 0,8 x 14, get the inequality group:

To solve the inequality group, 0 t is obtained, and the inequality group has no solution, so the defined domain of the function relation is [0, ].

2) To make x 10, there should be.

Simplify to get t2+4t 5 0

Get t 1 or t 5, from t 0 to t 1

**The subsidy is at least $1 per kilogram.

There are no drawings in the original title, and besides, how can I bring up the drawings here?

Direct deposit, fixed deposit, lump sum deposit and withdrawal for 3 years. For example, 10,000 yuan: 10,000 yuan.

One year: 10,000

Two years: 10,000

10,000 yuan: 10,000 yuan.

One year: 10,000

Two years: 10,000

Halo: This is obviously a microeconomics topic

lz you have a problem with the problem, and I thought it was some interesting math problem

Change the topic and the benefits will be better.

1. The volume is the base area multiplied by the height.

Rotate around its length to give a cylinder with a height of 4 base area and a radius of 3 with a volume of 3 2*4=36 cubic centimeters.

Rotate around its width to give a cylinder with a height of 3 and a radius of 4 at the base and a volume of 4 2*3=48 cubic centimeters.

2. The line obtained by the intersection of the surface and the line of the intersection of the two walls The point obtained by the intersection of the line and the road intersects the road.

1. The volume of the box around the 4cm side = *3 *4 = 36 The volume of the box around the 3cm side = *4 *3=48 2. For example: if there is a door on a wall, the wall is a plane, and the door is also a plane, then the edge of the wall and the door is their intersection line, and the intersection of the two intersecting edges of the door is the intersection of the line and the line.

1. Rotate around the length, then the radius of the bottom surface of the cylinder is 3, and the height is 4 volume = *3 2*4 = 36 cubic centimeters.

Rotate around the width, then the radius of the bottom surface of the cylinder is 4, and the height is 3

Volume = *4 2*3 = 48 cubic centimeters.

2. The surface intersects, for example, if a thin plate is inserted into the water, the plate surface and the water surface intersect in a line.

For example, folding a piece of paper is equivalent to turning a piece of paper into two sides, which also intersect in one line.

Lines intersect, for example, if 2 hairs are straightened and do not overlap each other, they should intersect at a single point. For example, if you look up at the roof, the length and width of the quadrangular roof can be seen as two lines, and they meet at one point.

1。The volume of a cylinder around a length of 4 cm is 48 base area multiplied by height = 4 squares multiplied by 3

The volume of a cylinder around a width of 3 cm is 36 base area multiplied by height = 3 squares multiplied by 42. Intersection of faces to face to get line: The wall meets the ground and the two adjacent lines of the horizon box intersect at a point.

1 Winding length: Winding width:

2 The line where two walls intersect The line where the ground intersects the wall, etc., The point at the corner of the wall is considered the point where the line intersects the line, etc.

Seems like your triangle adq should be ado If that's the case, here's the answer:

Because ab=4, bp=x, then ap 2=x 2+16, cp=4-x, because ad=4, the triangle ado area is y, so do=y 2, then co=4-y 2, ao 2=16+y 2 4

From the relationship of triangles, we can see that po 2=ao 2-ap 2=cp 2+co 2, then y 2 4-x 2=(4-x) 2+(4-y 2) 2, which is simplified to obtain y=x 2 2 2x 8

Wrong, Q did not appear in the question stem, why did ADQ appear later?

Untie; Set the channel width xm; According to the title,80×2x+（100+180）÷2×x-2x²=（100+180）×80÷2x1/6

300x-2x²=5600/33x²-450x+2800=0solution, x= discarded undesirable) or x

Solution: If the channel width is x meters, there is:

130x+2*80x-2x 2=1 6*(100+180)*80 2, that is: 190x-2x 2=280*80 122x 2-190x+5600 3=0

The result is: x=...

Set the channel width d

Then (100+180) 80 2 1 6=80x2d+140d-d

The solution is d-150 = (130 root number 3) 3 so d =

Set the width to x

100+180)x/2+2*80x-2x^2=80(1/6)(100+180)/2

The solution is x=?

Do the math yourself!

This kind of question should be done skillfully, starting with 5, estimating the single digit, and then pushing forward in turn.

435 15=29 Does the final number be equal to 2? The dividend must be less than 24, and the only ones in 1-24 that are divisible by 5 are 15 and 10, and the exclusion of 10 is only 15

In order to clarify unit 1, this topic can be described in more detail:

A dress costs 225, 225 is the price after 25% of the original price has been reduced.

The unit 1 of this problem is the original price, which is unknown, and should be done by division or equation.

The practice that others say is actually omitting a step, specifically:

The 1 4 in the equation is 25%, 1 represents the unit 1, that is, the original price, and it is regarded as the number 1, then the money of the price reduction should be 1 4, 1-1 4 means that there is 3 4 left after the price reduction (the unit 1 is the number 1), and the money left after the price reduction is equivalent to the number 1 with 1 3 4.

225 is equivalent to the number 3 4, then the number 1 is: 225 3 4 = 300 If 225 + 225 is the correct algorithm, this question should be changed to the original price of a piece of clothing 255, the price has increased by 25% (of the original price), what is the current price?

In short, the unit 1 of the price increase must be the original price, the known original price is found by multiplication, and the known current price is found by division; The unit of price reduction is also the original price, the known current price is found at the original price by division, and the known original price is found by multiplication. Unit 1 is known to be multiplied, unit 1 is unknown to be divided.

Unit 1 is the original price, known current price, unit 1 is unknown, use division.

Find a good unit 1 in units of original price 1

The current price is 1-25%=75%.

The original price is: 225 75% = 300 yuan.

Think of the original price as unit 1.

225 is 25% price has been reduced: (1-25%)=75% The original price is: 225 (75%) 300 (yuan).

But isn't it 225+225* according to the formula?

225 yuan is the selling price, plus what is 25% of it???

It's a matter of scores.

It regards the ** that comes here as "1" has been reduced by 25%, that is, 1 4, then the ** after the price reduction is 3 4 of the original price, that is: 1-1 4

So this problem is how to calculate 225 (1-1 4) Your algorithm is to find how much the price is after the price reduction, that is: 225*, and then use the ** after the price reduction, that is, how much is the price of 225+, that is, 225*, so you get your formula, that is: 225+225*

In this question, it is based on the original price of the clothes as the unit 1, that is, 1 represents the original price, and the so-called price reduction of 25% is 25% of the original price of the price reduction

x*(1-25%)=225, x=300 can be calculated

You are right to divide 225 by 3 4, because 225% of the price reduction is 3 4 of the original price

The price reduction is based on the original price. That is, the original price (1-25%)=225

I don't know if you can list equations, but it's very simple to solve them with equations.

That's the right question. "Unit 1" refers to the original price, not 225 yuan.

It's easy to solve this way:

Solution: Let the original price be x yuan, then.

Addendum: Otherwise, the original question is detailed: 225 yuan is a 25% price reduction compared with the original

The 1 you said represents the original price, which is reduced by 25% from the original, so your algorithm is wrong, if the column equation should be 225 (1-25%)=300

That is, to use the most direct equation analysis.

Don't look at the original price as 1, set the original price to X yuan.

According to the question, (1-25%)x=225

x=225/（1-25%）

x=300 should be quite clear, if there are any questions, tell me again!!

Let the original price of this dress be x

Then it gets: x=300

(74%-60%): 80%: 74%) = 7:3 Per serving: 500 (7+3) = 50 (grams).

80% takes: 50x7=350 (grams).

60% takes: 50x3=150 (grams).

Set the copper content to be 60% xg

x=150, so 60% copper should be 150g, and 80% copper should be 350g

Let 60% be x, then the other is 500-x. Then you can do the column equation. 74%*500=60%*x+80%*(500-x).Just get the answer!

The shortest distance should be along the outer arc, from point A in a straight line to point B at 2 o'clock.

This distance Pythagorean theorem can be obtained, ab= (6 +8 )

10 Think of the path of this line as a rectangular diagonal, with one side being high and one side being half the circumference of the circle.16 2=8. Do you understand.

Putting the sides of the cylinder, the straight-line distance between A and B is the shortest.

Half of the circumference of the underside is 8 cm.

The height is 6 cm.

According to the Pythagorean theorem.

64 + 36 = 100 = 10 squared.

So it's 10 centimeters.

The cylindrical and actually shortest route is the hypotenuse of the right-angled triangle with a circumference of one-half of the base (8 cm) and a height (6 cm) respectively.

It is easy to calculate, and the distance is 10cm

10cm, lateral back with the Pythagorean theorem.

10cm

Put the side AB on the surface.

It is a rectangle with a length of 8 and a width of 6, and the straight line between two points is the shortest.