2. If there are two related quantities A and B, and A B = K (certain), A and B are (inversely proportional), and A and B are called (inversely proportional).
3. If there are two related quantities A and B, and A = K (certain) of B, A and B are in (positive) proportional relationship, and A and B are called (positive proportional relationship).
5. The area of a triangle is constant, and the base is directly proportional (inversely proportional) to the height.
6. The bottom area of the cone is constant, and the volume is proportional to the height.
7. A right-angled triangle, with two right-angled sides of 30cm and 40cm respectively and an oblique length of 50cm. If the two right-angled sides of the circle are reduced by 1:5, the length of the hypotenuse becomes (10)cm, and the area of the triangle after reduction is (240) square cm.
Two. 20kg peanut kernel can extract 8kg oil. According to this calculation, how many tons of oil can be extracted from 100 tons of peanut kernel? How many tons of peanuts do you need to squeeze out 5 tons? I haven't done it yet.
4。 Binding a batch of books, it is planned to bind 2500 books every day, which will be completed in 30 days. In fact, 500 books are bound every day. Actually, it will take a few days to finish.
Solution: Suppose it was actually completed in X days. .
2500×30 = 500 times
7500 = 500 times
X=75000÷500
X= 150。 . Answer it yourself. .
5。 This publishing house publishes a science and technology book. If there are 600 words per page, it needs 80 pages. In order to save money, I decided to reduce the font size and arrange 200 words per page. How many pages does this science and technology book have now?
Solution: Suppose there is one now. . See for yourself in the middle
600×80 = 200 times
Do the math yourself
6。 On the map of 0-80- 160-240 (km), the distance between a and b is 8.4 cm. How many hours does it take for a car to travel from A to B at a speed of 64 kilometers per hour?
I messed it up. . I don't know if it's right or wrong. Don't blame me. .
240÷64=37.5 (hours) A: It takes 37.5 hours. . 、
I typed it verbatim. . Definitely not plagiarism. Give points. .