Ask a math question, thank you for being in a hurry 10

Huh .Let Xiao Wang's speed be x meters per minute, so Uncle's speed is meters per minute.

Uncle's speed is because 3 2=, because when Xiao Wang runs 2 laps, Uncle runs the track lap, so the ratio is 3:2, that is, Uncle's speed is twice that of Xiao Wang, understand? )

Also, 32 seconds = (32 60) minutes = (8 15) minutes * (8 15) means 8/15,"/"is divided by.

So, the equation is, (8 15)*(x+

4/3)x=400

x = So Xiao Wang runs 300 meters per minute, and Uncle runs 450 meters per minute.

The second part is:

The time they met should have been after Xiao Wang ran 2 laps, or Uncle ran to untie the lap.

Therefore, 400 meters * 2 = 800 meters, (that is, Xiao Wang ran 800 meters and met his uncle).

Minutes = 2 minutes and 40 seconds.

They met 2 minutes and 40 seconds later after they started in the same place and in the same direction.

The first question: Set the speed of Xiao Wang x and the speed of Uncle Y

400*2/x=400*3/y

32*x+32*y=400

The results are self-counting.

Second question: 400 (y-x).

1.Xiao Wang 5m s, uncle;

The latter two met again;

I'll just do the math for the 2nd floor.

It's boring.

I remember that the homework we left seemed to have a question, and that was it=.=~

1).When the last digit is 0, any two digits are selected as hundreds and ten digits respectively, and the permutation number a2 5=5x is used to tell the two methods of thick single digits; The remaining 4 non-zero numbers are selected in the hundred position and there are four methods, and the remaining 4 numbers are selected in the ten position and there are four methods, a total of 2x4x4=.

52 pcs. To get an even number, then the single digit can be 0, 2, 4.

First of all, take 0 as the single digit, then the hundred can have 1, 2, 3, 4, 5 five choices, the need for non-repeated numbers, then the ten digits are not for the remaining four choices, this method has 5 * 4 = 20;

Take 2 as a single digit, then there are only 1,3,4,5 four choices for the hundred, the same reason, but the ten digits can have 0, so the ten digits have four choices for Kaiqing, and this method has 4*4=16;

Finally, with 4 as the single digit, the hundred digits can have 1, 2, 3, 5 four choices, then the ten digits can have 0, and the ten digits also have four choices, and this method has 4 * 4 = 16;

Finally, add up these methods to the final answer: 20 + 16 + 16 = 52, so there are 52 such even numbers.

Idea: If you remove 3 from the series, the column is a series of equal differences with 3 as the tolerance.

The first term is known to be 2011, and as long as you know that the 326th number of this series is the first term in the new series, you can find the answer according to the formula of the equal difference series.

Think of it as a group.

Passed: 326 3 = 108 remainder 2

I learned that the 326th number was the second number in the 109th group of the original sequence, so in the first 108 groups, each group had 2 numbers in addition to 3; Then there are 108*2=216 numbers in the new sequence, and the first number in group 109 is 3

108*2+1=217

Then the 326th number of the original series is the 217th term in the new series, and then according to the formula of the equal difference series.

an=a1-(n-1)*3=2011-（217-1）*3=1363

3 numbers in a group,。。

The first column is all 3, the second column is 6 different for each number, the second column is 6 different for each number, and then the 326th number is ready.

The conditions are not sufficient, and it is not stated how many units there are on each floor. If it is arranged according to one ladder and two households (two households on each floor of each unit), Jiajia's home is located in Room 1708 of Building 2 (can be abbreviated as 2-1708);

Meimei's home is located in Room 805 (can be abbreviated as 4-805) in Building 4;

Xiao Gang's home is located in Room 1101 (can be abbreviated as 5-1101) in Building 5

The first number is the building number, the second number is the unit number, the third and fourth numbers are the floor number, and finally the room number:

Therefore, the door number of Jiajiajia is: 2-4-17-2

The house number of Meimeijia is: 4-3-08-1

The door number of Xiaogang's house is: 5-1-11-1

Jiajia lives at No. 2, 17th Floor, Unit 4, Building 2, house number: 241702

Meimei lives at No. 1, 8th Floor, Unit 3, Building 4, house number: 430801

Xiao Gang lives at No. 1, 11th Floor, Unit 1, Building 5, House Number: 511101

a(n+1)=1 3an+n (n is odd, n+1 is even).

Therefore. a2n=1 3a(2n-1)+(2n-1) (2n-1 is odd, 2n is even).

In a football league, there are a total of 10 teams, each team has to play 16 games against each other team, Zhaohong asked each team how many games to play, the answer is 144 games = 16*9

Let the proportionality coefficient of an be q

Then a(m-1) = am q a(m+1) = am*q into the equation. am/q*am*q-2am=0

am^2-2am=0

am-2)am=0

So am=2

Therefore, the general term of the proportional series is an=2, and the scale factor is 1, so tn=2 n

t(2m-1)=2^(2m-1)=128

2m-1=7

m=4, so the value of m is 4

Agree with the upstairs!

This seems to be a very deep prototype ...

If you don't understand it, can you determine it accurately?

Yes, if you take any point of p(x0,y0) on the image of the function y=f(x), then y0=f(x0)=f(-(x0)).

The coordinates of the symmetry point q on the y-axis are (-x0,y0), y0=f(-(x0)).

The point q(-x0,y0) fits the analytic expression of the function y=f(-x), that is, the point q is on the image of the function y=f(-x), and it can be seen from the arbitrariness of the point p that the image of the function y=f(x) and the function y=f(-x) are symmetrical with respect to the y-axis.