Junior high school mathematics seventh grade knowledge summary how to download? Urgent

Don't sum up, the examination questions are all from the questions you do. Just do more writing exercises. If you do it smoothly, it will be natural. It's useless for you to only know the knowledge. The questions always become more complicated

Idioms at the beginning and the end of Mao
It must be Mao

Volunteer
a drop in the bucket

The sum of 200, 300, 400, 500, 600 and 700 in the number of squares is equal to 1700
The six numbers 200, 300, 400, 500, 600 and 700 are respectively filled in six small circles, so that the sum of the four numbers in each square equals 1700
For example: 0-0-0
0-0-0 fill in the above numbers here, and the sum of them should be equal,

Because the sum of four numbers in a square is equal to 1700, that is, the sum of two squares is 3400, because the sum of 200, 300, 400, 500, 600, 700 is 2700, that is, the sum of two circles repeated in the middle is 3400-2700 = 700, so 300400 or 200500 can be added in the middle, that is, two cases, but obviously 300400 is not in line with the meaning of the problem

When x=______ The value of formula 2x-1 is less than that of formula 5x + 6 by 1

According to the meaning of the question: 2x-1 = 5x + 6-1, the combination of moving items: - 3x = 6, the solution: x = - 2

A bookshelf has three layers: upper, middle and lower. Xiaoming first puts one third of the books in the upper layer into the middle layer, then puts one fifth of the existing books in the middle layer into the lower layer, and finally puts the lower layer into the middle layer
One seventh of the existing books on the third floor are put back on the upper floor. At this time, there are 12 books on the third floor. How many books were put on the third floor?

After the upper layer is put into the middle layer, there are 12 books in the middle layer (1-1 / 5) = 15 books
After the middle layer is put into the lower layer, the lower layer has books 12 (1-1 / 7) = 14 (copies)
So there were books on the upper floor (12-14 × 1 / 7) / (1-1 / 3) = 15
There are 15-15 × 1 / 3 = 10 books in the middle
There are 14-15 × 1 / 5 = 11 books in the lower layer

The mass of rain is m, the initial velocity is 0, and the velocity when it falls to the ground
Supplement: any larger factor that cannot be ignored can be considered. Small factors can be ignored.
2. Suppose the landing speed is v2. When a person walks a distance of 1000 meters, his running speed is infinite from V1 to v2. When the speed is between V1 and V2, the amount of rain is in the middle. (the velocity is taken as V0, that is, when the velocity is less than V0, there will be more rain and when the velocity is greater than V0, there will be less rain.)

First question
If you don't give rain in the air, the relationship between velocity and friction
According to the law of conservation of energy
2MgH=MV*2
The speed is 100 times root 2
Second question

Two and one-third minus five fourths minus nine fourths?

I made a picture

The ratio of the number of cards collected by Xiaoming and Xiaogang is 4:3. If Xiaoming gives Xiaogang 18 cards, then the number of cards collected by Xiaoming is two-thirds of that of Xiaogang. How many cards do they have

It turns out that Xiao Ming accounts for 4 / 7 of the total number of the two
Now Xiao Ming accounts for 2 / 3 of the total number of the two people (1 + 2 / 3) = 2 / 5
Then the total number is: 18 (4 / 7-2 / 5) = 105
Xiaoming Original: 105 × 4 / 7 = 60 sheets
Xiaogang Original: 105-60 = 45

The sum of a natural number and its reciprocal is 5.2______ ．

2 into a fraction is 515515 = 5 + 15, 5 × 15 = 1; so the natural number is 5

How can these four numbers be counted as 24

(5-1/5)*5=24

Junior high school mathematics seventh grade knowledge summary how to download? Urgent