There is a question that I have thought about for a long time and have not come up with, to solve?

Yes. 1. Divide into 3 parts, 4 parts, take two points and put them on both sides of the scale, the uneven description is in this one, and the flat description is in the other part.

Take two balls and place them on both sides of the scale......

You should know, right?

Considering the dividend as 800 estimates the result is 400.

802 is estimated by the dividend as 800, and the result of the estimate is 200

Think of the dividend as 800 and the estimate is 200

The dividend should be reduced by 800. So it is equal to 800 4. Equal to 200.

It can be estimated with 800, and the result of the estimate is 200It's too simple for a fourth-grader.

The first empty time is 800, and the second empty time is 200

Solve the electricity cost per kilometer required by the newly purchased pure electric vehicle is X yuan, and the fuel cost per kilometer required by the original fuel vehicle is X + yuan.

From the title, 650 x 150 (x+

Solution, x = A: The electricity cost per kilometer of the newly purchased pure electric vehicle is yuan.

A and B do it in one day: 1 3 8 = 1 24

B C does it in one day: [2 3*1 4] 2=1 12 A B C does it in one day: [2 3*3 4] 5=1 10 Then A's efficiency is: 1 10-1 12=1 60 B's efficiency is: 1 24-1 60=1 40

C's efficiency is: 1 10-1 60-1 40 = 7 120 A did: 13 * 1 60 = 13 60, a total of money: 13 60 * 1800 = 390 yuan.

B did: 15 * 1 40 = 3 8, a total of money: 3 8 * 1800 = 675 yuan C did: 7 * 7 120 = 49 120, a total of money: 49 120 * 1800 = 735 yuan.

There is an ambiguity here: then B and C cooperate for 2 days to complete the remaining 1 4, this 1 4 refers to the 1 4 of all the work, or is it 1 4 of the 2 3 of the total work remaining after six days of cooperation between A and B?

Is this labor time or the result of labor?

A + B = 1 3 divided by 6 = 1 18

2 3 * 1 4 divided by 2 = B + C = 1 12

1 2 divided by 5 = A + B + C = 1 10

1 18 + 1 12-1 10 = B = 7 180 A = 1 18-7 180 = 1 60

C = 1 12-7 180 = 2 45

Assuming that the work efficiency of each person remains the same, A alone needs x days to complete, B needs Y days, C needs z days, from the question, 1 x + 1 y = 1 18, 1 y + 1 z = 1 1 12, 1 x + 1 y + 1 z = 1 10

The solution is 1 x = 3 180, 1 y = 7 180, 1 z = 8 180, and then considering the proportion of their total workload, A is a total of (6 + 5) * 3 180 = 33 180

B total (6 + 2 + 5) * 7 180 = 91 180 C total (2 + 5) * 8 180 = 56 180

Multiply by the total remuneration, and in the end A should get $330, B $910, and C $560.

Let the work efficiency of A, B and C be x, y, and z respectively

6（x+y）=1/3

2（y+z）=1/6

5（x+y+z）=1/2

Find x=3 180

y=7/180

z=8/180

That is, x:y:z=3:7:8 So the wages of A, B, and C are 300, 700, and 800 respectively

A and B cooperate, complete 1 3 6 = 1 18 per day

B-C cooperation is completed in 2 days (1-1 3) 1 4=1 6 B-C cooperation, 1 6 2=1 12 is completed every day

Three-person cooperation for 5 days to complete 1-1 3-1 6=1 2Three-person cooperation, daily completion of 1 2 5=1 10

A is completed every day: 1 10-1 12 = 1 60

B completes every day: 1 18-1 60 = 7 180 A completes in total: 1 60 (6 + 5) = 11 60 B completes in total: 7 180 (6 + 2 + 5) = 91 180 A deserves: 1800 11 60 = 330 yuan.

B deserves: 1800 91 180 = 910 yuan.

C deserves: 1800-330-910 = 560 yuan.

Because the absolute value and the value under the root number are greater than or equal to zero.

So there is m+1=0, 2n-1=0

m=-1, n=1 2

m^2000-n^4

Because both the absolute value and the root number cannot be negative, it can only be in the form of 0+0=0, so m+1=0, m=-1 2n-1=0 n=1 2 is brought in the back, and 1-1 16=15 16 thank you.

Because the absolute value is a non-negative number, and the square root of the flat arithmetic is also a non-negative number, so the addition of these 2 numbers is also a non-negative number, and the addition of these 2 numbers = 0, so it can only be that these 2 numbers are 0, so m+1=0, 2n-1=0

The solution yields m=-1, n=1 2

So the original formula = m 2000-n 4

I'll give you ideas, and I won't do it in detail.

This is a typical problem where the sum of non-negative numbers is equal to 0. The two added factors are not less than 0, as long as the two added factors are 0.

Connect am, and make a perpendicular line perpendicular to ab and point o through the m point, let the radius of the major circle be r, and the radius of the minor circle is r, then am=r, mo=r, ao=2, and the pythagorean theorem: the square of r - the square of r = 4;

The arc cd is half of the circumference of the great circle, and the arc ce is half of the circumference of the minor circle, ed=2r-2r, x= r, y= r, then x(x+y)=(2r-2r)(r+r)=2 (r's squared-r's square)=8

Does the length of arc cd, arc ce refer to half the circumference of two circles?