Mathematics is good at advancing quickly, fast, fast, fast, fast

The school bought a batch of books and put them in two bookcases, of which the first bookcase accounted for 58% of the books, and if 32 books were taken out of the first bookcase and placed in the second bookcase, the books in each of the two bookcases would account for half of the books. How many books are there?

Solution: According to the title, 58%-1 2 is exactly 32 books, so 32 (58%-1 2)=400 books.

A: There are 400 books in this batch.

Reduced to 3 5 m²: hectares to the simplest integer.

3 5 square meters = square meters = 60 square decimeters = 6000 ordinary centimeters.

hectares = square meters = 1,500,000 square meters.

Ratio 2 3 kg:ton Ratio value.

2 3 kg: tons = (2 3) :(300

5 square meters = square meters = 60 square decimeters hectares = 15,000 square meters (if you have learned the unit of acres, you can turn it into 150 acres) (note the advance rate: 1 square kilometer = 100 hectares, 1 hectare = 100 acres, 1 acre = 100 square meters, 1 square meter = 100 square decimeters, 1 square decimeter = 100 square centimeters, and the rate of progress between adjacent units is 100).

3 kg: tons = 2 3 kg: 200 kg = 2 3 200 = 2 3 1 200 = 1 300 (the ratio cannot be written as 1:300).

According to the title, 58%-1 2 is exactly 32 books, so 32 (58%-1 2)=400 books.

square meters = 600 square decimeters, 1,500,000 square meters.

Question 3: 1:300

Question 1: 400 copies.

Question 2 6,000 square centimeters, 1,500,000 square meters.

Question 3: 1:300

Don't worry, it's too simple, the primary school is still the first year of junior high school, and the formula is 3 8 + x 9 + x 8 = 3 4

10 times 10 = 100 minus 4 = 96 divided by 4 = 24

Hopefully, thank you!

Hello: It turned out to be: 3000 80%=3750 yuan This commodity has decreased: 3750-3000=750 yuan I am glad to answer for you, I wish you progress in learning! The Learning Guide team will answer the questions for you.

If you need help with other topics, you can turn to me. Thank you!!

Solution: Step-by-step solution.

Original price: 3000 yuan).

3750-3000=750 (yuan).

Comprehensive solution. 3000 (1 yuan).

A: This product is reduced by 750 yuan.

Solution: Set the original price of the refrigerator to x.

1. 80%x=3000

x=3000/80%

x=3750

2.3750-3000 = 750 (yuan) Answer: This commodity is reduced by 750 yuan.

3000 80% 3750 yuan (original price) 3750-3000 750 yuan (reduced money).

Original price: 3000 80% 3750 (yuan).

Reduced money: 3750-3000 750 (yuan).

A: This product is reduced by 750 yuan.

It turned out to be: 3000 80%=3750 yuan.

This commodity is reduced: 3750-3000=750 yuan.

Original price: 3000 80%=3000 yuan).

Decrease: 3750-3000=750 (yuan).

A: This product is reduced by 750 yuan.

3000 divided by 8/10 equals 3750 (yuan).

3750 minus 3000 is equal to 750 (yuan).

3000x2 8=750 Solve problems in the simplest way, which is my consistent style.

Solution: The original price of the refrigerator is x 80% x = 3000 x = 3750 3750-3000 = 750

10. There is no easy way to solve the system of equations, which is to eliminate the element, reduce the ternary to binary, and finally become the unary to obtain the solution. If you don't even move your hands, don't count on it.

11. Set x sheets to make the box body, and Y sheets to make the bottom of the box. Then look for the equivalence relationship.

The first equal relationship: make a total of 190 sheets of iron sheets on the body and bottom of the box.

The second equiquantity relation: the number of the bottom of the box is twice the number of the body.

12. Can't see clearly.

13. Set the original price of A at x yuan and the original price of B at y yuan. Then look for the equivalence relationship.

The first equivalence relation: the sum of the original price of A and the original price of B is 1000.

The second equivalence relationship: the sum of the price reduction of A (90% of the original) and the price reduction of B (the original times) is 5% higher than the original **sum (the original times).

Only solution ideas are provided, not ready-made answers.

It's a long question, so let's do it slowly.

It's too lazy... 8th grade?

3.-1/4x^3y^4z^5

6.-6x^2+18xy