I have a math problem, could anyone help me look at it! Analyze! Fifty fortunes are worth it!

The answer is 3, divide the remaining 8 numbers by 3, and you can get the remainder.

According to the remainder, it is divided into 2 groups, the first group is 7, 13, 19, all surplus 1; The first group is 5, 11, 17, 23, 29, and all 2.

It can be found that the numbers of the first group and the numbers of the second group add up to multiples of 3.

So when 3 is in the middle, the sum of the straight lines must be prime, and it must not be divisible by 3, so each set of numbers can only be on a straight line with the numbers of the same group.

And each group is an odd number, so there must be a number of the first group and a number of the second group in a straight line, and the sum of the numbers on the line is a multiple of 3, not a multiple.

Therefore 3 can no longer be on the middle circle.

The first thing to think about when encountering this kind of problem should be: try out the possibility as much as possible, and then simplify and try several situations.

Then let's look at this question specifically:

Step 1: Start by listing all prime numbers between 19-71: 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 71.

As for why it is between 19 and 71, the main reason is that the minimum prime number obtained by adding 3 of the 9 prime numbers given in the question is 19, and the maximum prime number is 71, so you can now list all the cases of the sum of the three numbers. That's 12 situations.

The above has narrowed down the original large range to a certain range, so let's try a few cases.

One. Let's say the middle is 3

Starting from the maximum 29, i.e. the number of 29+3+x is equal to a prime number between 19-71 x satisfies the case of 5 or 11

i.e. 29=> 29---3---5 11

Here's how it goes: 23=> 23---3---5 11 17

19=> 19---3---7 *Uniquely determined.

13=> 13---3---7 *Uniquely determined.

I feel like I tried it out the first time, and the combination of 19, 13 and 3 is only 7, and 7 is only one. Explain that 3 puts 19 and 13 in the middle, and there must be a line that is not a prime number after combining it with 3. That is, you get 3 in the middle can not be filled...

Generally, the questioner of this kind of question that needs to be tried should consider that you don't have to try too many times, usually 2-3 times to try out, if you are interested, you can carefully try several other situations to see if it meets the requirements of the question, but in order to do the question, you don't need to.

Answer 3 to this question

Xie Yuan's nuclear envy replied to Tang Chang:

22-7=15 (yuan).

15 The maximum distance between A and B is:

10+3=13（km）

y=messy hand 0x 3

Pick D. The square rotates in the circle, that is, the side length of the square or the opposite side is the radius to do circular motion, because the side length of the square and the radius of the circle are equal to Zheng Xiao is 1, and the branch manuscript is shouted when the two ends of one side of the square are on the circle, then the circumferential angle is exactly 60 °, that is, 3, the corresponding chord length is the side length of the square, and the observation point b to the point c contacts the circle, it can be seen that the angle of movement is 120 ° -90 ° = 30 °, and the 90 ° here refers to an inner angle of the square, namely 6, that is, then the square turns a circle, and the point a takes the point b, c, d as the center of the circle to do the radius 1, 2 (the circular motion of the length of the diagonal line of the square, the corresponding circumferential angle is 6, that is, the circumference is 1 12, so there is a rectangle rolling the length of the trajectory of the point a = 2 12 + 2 12 + 2 12 = 3 + 2 6;The square is 4 3 for a week, then the point a and the point p coincide to find the least common multiple of 2 and 4 3, then the square rolls 3 times completely, so the trajectory length of the point a = 3 · ( 3 + 2 6) = (2 + 2) 2

Select D, see the figure below for a detailed explanation of the limb posture and the detailed calendar.

Connecting the two points of O and AB, it is easy to know that OAB is an equilateral triangle, then the central angle of the circle is 60° when the side of the square is the chord, and after 4 rolls, the AB side returns to the circle, at this time, the square rotates 4 60=240°

The central angle of the circle is 360°, and the least common multiple of 240 and 360 is 720, that is, when point A rotates 720°, it returns to point P, and the square rotates a total of 720 60 = 12 times.

That is, the square has been rotated three times.

When the positive tie chain square rotates once, the angle of rotation of point A is 90 °-60 ° = 30 °, that is, 6, then for point A, the distance passed by the first rotation is 6 ab, the distance passed by the second rotation of the first loose car is 6 ac, the distance of the third rotation is 6 ad, and the distance of the fourth rotation is 0

Therefore, from the beginning of the rotation to the AB edge to re-contact the circle, point A passes through 6 (ab+ac+AD)=(2+ 2) 6, and the square is rotated 3 times, so the actual rotation distance of point A is 3 (2+ 2) 6, i.e., the actual distance is (2+ 2) 2·

Which digit can tell me about this problem, can you tell me about it, and if so, which god of mathematics can tell me about this problem? If you want the dormitory to explain it to you loudly, then ask the homework teacher of the professional school to explain it to you in the future, and you will be very acceptable after talking about it.

Daddy Speed: Little Red.

Dad took Xiaohong to C and put her down to pick up Mom.

Therefore, the distance from Dad to Mom is 2 parts;

D is the distance traveled by Dad and Mom when Xiaohong arrived at C; d to dad to pick up the point of the distance is 2 5 servings;

Then, the route of launching AD is 3 to 5 copies;

To sum up, it is concluded that there are 4 parts of AB's journey, Dad has not stopped from A to B, and has been traveling on the road, and Dad has driven a total of 8 parts; That is, the whole AB process is done 2 times;

So, a family of three spends a total of 100 2 40 = 5 hours

The problem you are talking about, belongs.

Itinerary problems in middle school math or physics.

This problem is a rare high-quality problem.

Here's what I think—

There are many ways to answer this question. I use a stupid approach that is particularly easy to understand.

Suppose Dad rides a motorcycle to carry Xiaohong away T1 time, puts down Xiaohong, and goes back to pick up Mom, the time when Dad meets Mom is T2, and Dad meets Mom and takes T3 time to reach my aunt's house, at this time, Xiaohong also reaches at the same time.

Little Red's Stroke: 40T1 + 8T2 + 8T3 = 100 Mom's Stroke: 8T1 + 8T2 + 40T3 = 100 Dad's Stroke:

40t1 +40t2 + 40t3 = 100 + 2*40t2

Solving the above system of ternary equations yields:

t1 = t3 = 15 8, t2 = 5 4 The time for Xiaohong's family to arrive at her aunt's house is: t1 + t2 + t3 = 5 (hours).

The above answers are for your reference.

Actually, Dad walked that road twice.

100x2 40 = 5 (hours).

Hello, please take a picture and send it to me!

This is a math problem, so if the math problem is solved, he must have solved it according to some formula.

The process of math problems is not important, if you think about the problems, you need to be patient with the problems.

You do math problems and hope to help you solve them and see what kind of problem it is. I haven't seen it yet.

This has a mathematical hope, good finance, or can you check the way, the process praise, and it is too expensive.

It's a math problem, and I hope you're kind. Can you help me out. It's the process that matters. This is no wealth. This will not be begged by the great gods.

The three time periods are set to , then:

Little Red 40a+8(b+c)=100

Daddy 40a-40b+40c=100

Mom 8 (a + b) + 40c = 100

Solve the equation to obtain: a=15 8

b=5/12

c=15/8

Total time: 15 8 + 5 12 + 15 8 = 35 12 hours.

Draw this scenario, and the geometry of the grass it can eat is three quarters of a circle with a radius of four and two circles with a radius of one quarter, so the area is 3 4*

It can eat 3 4 of the radius of a circle with a radius of 4 + 1 2 of a circle with a radius of 1 meter

A: The area where sheep eat grass is square meters, I don't know, right! My math foundation is also very poor!

The sum of the areas of the two small grasslands in the figure is s2=1 2*(

The total area is s=s1+s2=

So the area where sheep can eat grass is square meters.

During the summer vacation, Xiaohua and Xiaolin both chose the same swimming pool to learn to swim. Xiaohua goes every four days, and Xiaolin goes every six days. The two went to the swimming pool at the same time on August 1, how many times will they meet again in August? What are the dates?

A: They will meet again twice in August. August 13 and August 25 respectively. (i.e. find the least common multiple of 4 and 6).

The 13th and 25th met on these two days.

Xiaohua goes once every 4 days, so the frequency of his visit is 1 time, 4 days Xiaolin is 1 time for 6 days.

If they are to meet, it must be a day with the same denominator.

Then it's twelve twenty-four !

1 + 12 = 13 1 + 24 = 25.

I hope you're satisfied.

The common multiple of 12 is

They will meet again twice in August, on August 25th

The number of times Xiaohua went in August was 8, and the number of times Xiaolin went in August was 6

The period in which Xiaohua and Xiaolin can meet is 12

The dates they met were;

You now have a maximum of 65 wealth

How do you give 100 an explanation.

Let's say the installment time is x years.

From the title, it can be seen that the amount of money and time of the two installments are the same, so.

The first stage: 23+5 (x-1).

The second installment: 8*1 2x+

23+5（x-1）=8*1/2x+

The solution of x = 8 money is 580,000 yuan.

Because the one-time payment can be discounted by 10,000 yuan, the one-time payment is 10,000 yuan, so it is cheaper to choose a one-time payment.

Suppose: If the term of the two installment payment methods is x years, then the total price of the first payment method.

23+（x-1）x5。

The total room rate for the second payment method.

1/2）xx8+（1/2）。

The total house price is equal and there are:

23+(x-1) 5=(1 2)xx8+(1 2) solution: 23+5x-5=4x+

x = 8 years. Total house price = 23 + (8-1) 5 = 23 + 35 = 580,000.

3 p.m. is 15 p.m.

15-8=7 (hours) After Wheel A reaches C, it takes another 7 hours for B to arrive.

The speed of A and B is considered as 4 parts and 3 parts respectively.

3 7 (4+3) = 3 (hours) This distance is shared by A and B for 3 hours.

8 + 3 = 11 11 points meet.