For example: x: y = 0

Then, when x=0 and y changes, x cannot be changed. The two are out of proportion! ! !

-Trust Brother! My brother studied mathematics in college! Hey hey.

direct ratio

If the ratio of two dependent variables is constant, these two quantities are called proportional quantities, and the relationship between them is called proportional relationship. Y = kx (k is not equal to 0)

1) ratio: two related quantities, one changes and the other changes. If the ratio (that is, quotient) of the two numbers corresponding to these two quantities is certain, these two quantities are called proportional quantities, and the relationship between them is called proportional relationship. ① Represented by letters: If the letters X and Y are used to represent two related quantities, and K is used to represent their ratio, the (certain) proportional relationship can be expressed by the following relationship: ② The proportional relationship is the changing law of two related quantities: it expands and contracts at the same time, and the ratio remains unchanged. For example, if the speed of a car is constant every hour, is the distance traveled proportional to the time spent? The above manufacturers are certain, so dividend and divisor represent two related quantities, which are in direct proportion. Note: When judging whether two related quantities are directly proportional, we should pay attention to these two related quantities. Although they are also a quantity, they change with the change of another, but the proportion of the two numbers they correspond to is not necessarily, so they cannot be directly proportional. Such as a person's age and weight.

The relationship between y and x

When k > 0, y increases with the increase of x, and when k < 0, y decreases with the increase of x.