We will investigate whether two variables ( x and y ) varies directly with each other and determine the corresponding constant of variation.
We have the following relation at hand:

First to determine the whether the relation is "direct" we will resort to the following definition:

We will apply the above definition of " direct " relation to the problem as follows:

We substitute increasing values of ( x ) in the given relation and track the corresponding values of ( y ). We see that as ( x ) increases then ( y ) decreases.
The above result denies the definition of a direct relation. Therefore,
