What quantities are directly proportional a) the cost and quantity of the goods b) the length and width

What quantities are directly proportional a) the cost and quantity of the goods b) the length and width of the rectangle with a constant area c) the height and age of the child d) the edge of the cube and its volume e) the value of the fraction and its significance as the numerator

Direct proportional dependence – if one number increases, then the value (it depends on the number) also increases.

1. The cost and quantity of goods is a direct proportional relationship.

1 kg of sweets – 120 rubles

2 kg of sweets – 240 rubles.

With an increase in the number of kg of sweets, the total purchase price also increases.

2. The length and width of a rectangle at a constant area are inversely related quantities.

Length 6 cm

Width 1 cm

Area 6 cm2

Reduce the length by 3 cm

In this case, the width will increase – 2 cm.

The area is 6 cm2.

3. The height and age of the child.

As the child grows up, his growth increases. The values ​​are directly proportional.

4. Cube edge and volume – direct proportional relationship.

The longer the edge of the cube, the greater the volume.

5. The larger the numerator, the larger the fraction. The values ​​are directly proportional.