Grade 1 math problems, Grade 1 math problems.

Set the list price as X yuan, according to the list price ** profit (x-2000) yuan per piece, according to 80% of the list price ** profit (80% x-2000) yuan per piece.

or force reduction (x-2000) - (80% x-2000) = (x-2000) * 60%.

x=3000 yuan.

That is, the price of the product is 3,000 yuan.

If the price of the commodity is x, then according to the title:

x-2000)(

x=3000

where (x-2000) is the profit according to the list price**, and then multiplied by (for the current profit, establish an equation to solve.

Set the price to be $x, then.

80%*x-2000=(x-2000)*(1-60%)The solution of x=3000

Therefore, the price is 3000 yuan.

Expressed in scientific notation).

2. Keep three significant figures 13040000 = approximately equal to).

00256 The approximate number that retains two significant figures is, or.

Solution: Let the price of the commodity be x, according to the meaning of the title:

80％x-2000+=x-2000

Solution x=3000

After the discount, the ballpoint pen is each yuan, and the pen is yuan.

Ballpoint pens buy 22 is yuan.

Each reduction of a ballpoint pen plus a fountain pen is more than three cents, so you can buy up to 3 fountain pens when the total price is less than 100.

That is, there are three options:

Ballpoint pen Fountain pen.

As a mathematics in the first year of junior high school, this question mainly examines inequalities.

Here's how it works::

If there are x dormitories, then the number of males is 5 (x+1) and 5 (x+1) <35 1 according to the title

There are 8(x-1)>5(x+1) 2

1 2 is solved to get 13 3, and since x is an integer, x=5

The number of people is 30

Solution: There are x dormitories.

5x+5＜35

8(x-1-1)＜35

Solution, x 6, because the number of dormitories should be an integer, so, x=5, when x=5, the number of students is: 5x+5=5 5+5=30

A: There are 5 rooms and 30 boys

There are male x people, dormitory y room, by the title: x<35, 5y+5=x, 0<8(y-1)-x<8

Substituting formula 2 into formula 3, we get 13 3 so rounded, in summary: x=30, y=5

Thanks, ah.

You don't have a few factors to make a diagram, you don't know where the ship is, so you don't know where point d is, or you can take b as the origin and make a d and then find a point and draw the ship at 30° east north and measure the angle d to a. (Pure hand-played.) Give points. ）

Landlord, I'm a student in the first year of junior high school, I wrote this question, because it should be -3, not 3, if the question is different, I'll send you an answer to -3 for your reference: (-3) divided by (-6) -4 + 10

3) Multiply (4-10)-(6).

6) Divide by (-3) by 10+4