Math problems, the process is better to be complete, math problems, the process is complete?

Elementary School Olympiad.

1.After a distance of 25 kilometers, there was a battle at a distance of 1 kilometer, so the chase was 24 kilometers.

24 (8-5) = 8 (hours).

2.When Xiao Wang turned around, the team walked a thousand kilometers It takes 6 6 = 1 hour for Xiao Wang to go back.

At this time, the team is still walking, and when Xiao Wang chases the team, the team has already gone (1 + chasing team needs (1 + hour) Here according to the starting point (5 + kilometers.

Total distance 30 + 2 = 32

3.The distance from the start of the train to the time when the train is fully connected is the bridge length plus the train length.

The distance traveled by the entire train on the bridge is the length of the bridge minus the length of the train.

Therefore, the sum of the two times is twice the time it takes for the train to cross the bridge.

The subtraction of the two times is the time it takes for the train to pass twice the length of the train itself.

Speed = 2*1000 (60+40) = 20 m seconds.

Vehicle length = 20 * (60 - 40) 2 = 200 meters.

1.First of all, clear your mind and fight at a distance of 1 km, that is, 25-1 = 24 km.

The difference in speed is 8-5 = 3 km h, so the time: 24 3 = 8 h, the equation: let the pursuit x h hour take place the battle, there is.

8-5）x=25-1

2.The main point of this question is to find out the meaning of the question, from the meaning of the question, it can be seen that the speed difference between the students and the team is 6-4 = 2 kilometers per hour, and the difference between the student's acquisition and departure time is one hour, which is the distance between the student and the team is 4*km.

When the student catches up with the team, the time is 10 2 = 5 hours, and the distance covered at this time is 6 * 5 = 30 kilometers.

So the distance between the school and the farm is 30 + 2 = 32 km.

Column equation, let the distance between the two places be x kilometers, there is.

x-2）/6 = 4*（

3.The distance traveled from the beginning of the train to the complete departure from the bridge is the length of the train plus twice the length of the bridge, so it can be seen from the conditions that (1000+2x) 60=1000 40 x is the length of the train, and the solution is x=250

The velocity is 1000 40 = 25m s or (1000 + 250 * 2) 60 = 25m s

1. Set x hours.

8-5）x=25-1

x=82, set the distance s

It is equal to the time from returning from Xiao Wang to catching up.

s-2-4*

s-8）/2=（s+4)/3

s=323, the time of the whole train on the bridge is 40 seconds, which means that the train takes 40 seconds to get on the bridge at the end of the train and leave the bridge at the end of the train.

Therefore: vehicle speed: 1000 40 = 25 m sec.

The distance from the beginning of the train on the bridge to the complete departure from the bridge is exactly one train length, body length: 25 * (60-40) = 125 meters.

1. Solution: The difference between the speed of the enemy and the enemy is 8-5=3,25-1) 3=8Answer: A battle occurs after 8 hours.

2. Solution: Set the school to the farm for x kilometers, that is, walk 6 kilometers before returning. Rule.

6+x)-2) 6+ x=32A: 32 km from school to farm.

3. Solution: Let the length of the train be x, and the speed will be (1000+x) 601000+x) 60=(1000-x) 40 x=200 meters.

1000+200) 60 = 20 m seconds = 1200 m min.

A: The train is 200 meters long and the speed is 1200 meters per minute.

Indefinite integral formula:

The indefinite integral of lnx is xlnx-x+c.

0dx=cx^udx=(x^(u+1))/(u+1)+c

Support for 999**. Be more detailed:

Let a=1, b=1, and c=9 first

Then: (a+c) b= n+c

1+9) 1=1 1+9 (because n=a b) 10 1=2+9=11 (because 1 1=2).

Then set a=10, b=1, c=9

Then: a (b+c)=n 2c (because n=a b)10 (1+9)=10 1 2*9 (substitute 10 1 11) i.e. 10 10 =-7

Solution: Because 1 1 = 2, (1 + 9) 1 = 2 + 9 = 11, i.e. 10 1 = 11

10 (1+9)=11-2*9=11-18=-7, so 10 10=-7

40 pages, if x pages were read on the first day, 9x pages remained; On the second day, pages x+6 were read, and pages 9x-6 were unread = 3*(x+6) pages. x=4, so the total number of pages is 40.

I read 1 10 of the whole book in the morning, and 1 4-1 10 = 3 20 in the afternoon, so I read 3 20-1 10 = 1 20 more in the afternoon than in the morning, so the number of pages is 6 divided by 1 20 = 120

A: 120 pages.

There are x pages.

I read 1 10x in the morning and 1 10x + 6 = 1 4x in the afternoon

Let's ...... below

If you read page x in the morning and read page y, then y x=1 (9+1) (2y+6) x=1 (3+1).

Solution: x=120, i.e. 120 pages of the book 12 pages read in the morning.

AEC=Connected AC then the triangle ABC is an isosceles triangle.

Because AE is perpendicular to BC

So be=ec is the midpoint of bc.

Connect AC such that since AE is perpendicular to BC, E is the midpoint of BC.

Solution: Even FB ef perpendicular bisector ab fa=fb hand smile fba = slippery potato dust fab = 1 2 dab=40°

CDF CBF(SAS) CDF= CBF=100-40=60

Connecting FB, because FE bisects AB perpendicularly, then the triangle ABF is an isosceles triangle Qingzhi lead shape, and because the angle DAB is equal to 80 degrees, AC is diagonal, so the angle Fab is equal to 40 degrees, then the angle FBA is also equal to 40 degrees, it is not difficult to answer that the triangle DAF is all equal to the triangle BAF, so the angle ADF is also equal to the violent difference of 40 degrees, so the angle CDF = 180-80-40 = 60 degrees.

(1) The original equation can be reduced to: (2k-1)*x 2-8x+6=0 If the original equation is a quadratic equation, if you want to make the original equation have a real root, you only need to make 0.

64-24*（2k-1）≥0

Solution: k 11 6 (k≠1 2).

If the original equation is a univariate equation, 2k-1 = 0

Solution: k = 1 2

So, the largest integer solution of k is 1.

2) When k=1, the solution of the original equation is: +=8, *=6 + =( + *

So, the original formula is equal to 4 3 6.

(1)(2k-1)x2-8x+6=0 Because there is a real root, (-8)2-4*(2k-1)*6 is greater than or equal to 0, so k is less than or equal to 11 6

Because find the solution of the largest integer.

So k=12)x2-8x+ value is 2