Mathematics problems in the first year of junior high school, urgent and urgent, extra points can be

1.The sum of the internal angles is 180*(n-1).

Then let us design an n-side, then 180*(n-1)=2008, solve this equation, if the solution is an integer, it is fine, otherwise it will not work, because the n of the n-side must be an integer.

If B wins the tenth set, then A may be 1 or 2 points higher than B at the end of the ninth set.

Then discuss the situation: A and B played a total of 9 games of Go, A won a game for 1 point, B won a game for 3 points, A more than B for 1 point.

Or A and B play a total of 9 games of Go, A wins a game worth 1 point, B wins a game worth 3 points, and A has 2 points more than B.

Then solve the equation in two cases, and then find the answer, this should be done.

3.(300-20*5) 15=40 3, it is just right to have 40 Type B cars, and since the car cannot be a fraction, at least 14 Type B cars are required.

The distance two people have to walk together per hour.

5.The weight of 6 cm thick plexiglass is: (2*2*ton.)

The volume of liquid raw materials of this weight is: cubic meters.

The height of the liquid raw material: m = 8cm

It can also be calculated by weight ratio, the unit weight ratio of liquid raw materials to solids is::4

The volume ratio of liquid to solid state is 4:3 for the same weight at a time

Because the base area is the same, the ratio of liquid to solid height is 4:3

The height of the solid state is 6 cm, so the height of the liquid state is 8 cm

6.Set to exceed after x months.

After X months, Xiao Ming has 168+16x, and Xiaoli has 85+25x

According to the meaning of the topic: 85 + 25x> 168 + 16x and then solve it yourself, x>9 and two-ninths, can only take an integer, so x should take 10

First, set A type x bottle, B type (140-x) bottle.

You can find x=80 and buy 60 bottles of type b.

2, (3) Set A X bottle, B (200-X) bottle.

Investment: > 1420

x<120

Take Profit: (Greater than or equal to 339.)

Greater than or equal to 339

Less than or equal to 71

x is greater than or equal to 142

Then take the values that match the two.

This three seems to have miscalculated, and you can calculate it yourself, and I'm dizzy.

9.The speed of the ship is x, the downstream is x+4, and the reverse water is x-4

x+4）*3=（x-4）*5

Then solve this unary equation yourself, and x should be equal to 16

The distance is (16+4)*3=60

10.It is to find if 18 minutes to run for a few minutes, because the more you run, the less time you have.

If you run for x minutes at this time, you will walk for 18-x

Column equation: 210x+90*(18-x)=2100

Then it's up to you to solve the equation yourself.

Big brother, ten questions. I sweat ... You want to kill us.

Let's find the answer to the reference book

Analysis and Answer: There are only two ways for students A and B to travel: cycling or walking, because they travel alternately, from the statistical point of view:

The distance traveled by A + the distance walked by A = the distance traveled by B + the distance traveled by B.

A's riding time + A's walking time = B's cycling time + B's walking time.

Arrive at the same time) the distance traveled by A on a bicycle + the distance traveled by B on a bicycle = the whole distance.

Assuming that the whole distance is 100 kilometers, and the distance traveled by A is x kilometers.

Then the equation is available.

100-x)/3+x/15=(100-x)/15+x/5

100/3-1/3*x+1/15*x=20/3-1/15x+1/5*x

1/5*x+1/3*x-1/15*x-1/15*x=100/3-20/3

2/5*x=80/3

x=80/3*5/2

x=200/3

i.e.: x=66 and 2 3).

The time for the complete journey of line A is (100-200 3) 3 + 200 3 15 = 140 9 (hours), i.e., 15 and 5 9 hours.

The average speed of the whole journey is: 100 140 9 = 45 7 (kmh), that is: 6 and 3 7 km/h.

It can also be assumed that the whole distance is in other data or letters, and the average speed remains the same, except for the time difference, which is still 45 7 (km h), i.e., 6 and 3 7 km h.

(1) What is the single digit number of 3 2006? is divided by 4 and the balance is 2.

2) Knowing that the positive integer x satisfies x 5=6436343, find the value of x because 10 5=100000, 10 6=1000000 is 7 digits, and 2 6=64 so x is 2 digits 23.

The altitude of Camp 1 should be.

8000-[-20-(-47)] meters.

You definitely spend more time typing and writing this question than it takes to solve it.