What is the constant of variation, k,

Given two variable which are either directly proportional to each other or inversely proportional to each other, the constant of variation k is the number that relates these two variables

The K-constant variation is the factor of the increase-decrease relationship between the x-variable and y-variable which can be stated as y=k*x or x=y/k. For example, if y variable equal 5 and the x variable equal 2 then the k-constant variation equal 2 (calculation y=k*x - - > 5=2*2.5). This constant shows the relationship between the variables.