2. The proportions are all equal.

3. Unit price, unit price (certain) = total price/quantity

4. Answer: The total price and quantity are two related quantities, and the ratio of the total price and quantity is always the same, so the total price is directly proportional to the quantity.

The quality of apples is in direct proportion to the number of boxes.

3. 1.40 33

2. A: Dad's age changes with Cao Jie's age. Dad is older than Cao Jie.

They are out of proportion in age.

Four. sketch

1.2 3 5 6

8 12 20 24

2. The circumference of a square is in direct proportion to the length of its side.

I. 36-60 84

leave out

3. The total price and quantity of the subscription to "Youth World" are two related quantities, and the proportion of the total price and quantity is always certain, so the total price and quantity are directly proportional.

4.48 6

2. Be in direct proportion and judge in proportion.

Three. 4000 6000 8000

A: In direct proportion.

I 120 80 60 48 40 ...

1. All products are 24.

2. Total distance, time × speed = distance (determined)

3. Speed and distance are two related quantities, and the ratio of time and speed will never change, so time and speed are inversely proportional.

Two. 1. 100 50 20 105 2

The product is always 100.

3. Large denomination, small denomination × number of sheets = large denomination

4. The face value of RMB and the number of sheets are two related quantities, and the product of the face value and the number of sheets is always constant, so the face value and the number of sheets are inversely proportional.

Three. 1. The remaining pages vary with the number of pages read.

2. Out of proportion

4.√√

1. 1. Truck load × truck quantity = total material weight (certain)

be in reverse ratio

2. Total material weight ÷ number of trucks = truck load (specific)

Proportional

2. 1.

2.y÷x=k (certain)

3.5 days coal 1.5 tons, 2.4 tons can be used for three days.