(1) The area of each brick is fixed, and the occupied area is (positively) proportional to the number of bricks.

(2) The total number of students in each grade is certain, and the number of students in each class is (inversely) proportional.

(3) If 8/x=y(x is not 0), then x and y are inversely proportional.

2. Give a sentence.

(1) The divider is fixed, and the upper river divisor is inversely proportional. (√ )

(2) Weight is directly proportional to age. (× )

(3) The sugar content of sugar water is constant, and the sugar water ratio is typical. (×)

(4) The orientation is directly proportional to the river. The circumference of a square is proportional to the length of its sides. (√ )

(5) The area of a circle is proportional to its radius. ( × )

(6) The area of a triangle is constant, and its base and height are typical proportions. ( √)

4. Complete the relationship according to the relationship among the three quantities of rectangular area, length and width.

(area) (certain), (length) and (width) are inversely proportional;

(Length) (certain), (area) and (width) are in (positive) proportion;

(Width) (certain), (area) and (length) are in (positive) proportion.

5. For a fraction, the difference between denominator and numerator is 12, and the ratio between numerator and denominator is 1: 4. What is the score?

12÷(4- 1)=4

Denominator 4× 1=4

Molecule 4×4= 16

Score 4/ 16 problem supplement 20 10-03-23 20: 14

3. Total price/yuan |12 | 24 (36) 44 (160) 612 | Because the unit price = 12/3=4, the total price (above) = (below) quantity ×4.

Quantity | 3 (6) 9 (11) 40 (153) |

This is a grid. I can't type it. That's all I can do. I hope you can understand.

x | 3 | 4 | 6(8) 12 | 48 | 144

Y | 24 (18)12 | 9 (6) (1.5) (0.5) x is inversely proportional to Y = 72.