In schools, students are taught that if every y value in a function is achieved by multiplying every x value by a constant number, then that function is a direct variation. The formula used for direct variation is y=kx, where k is the constant of the direct variation. A constant in direct variation is a number which relates to the two variables which are directly proportional to each other. The steps followed in order to solve direct variation problems are: Step 1: Get the correct direct variation equation. The equation used to solve the problems is y=kx. When solving a direct variation word problem, however, you must consider using other variables apart from x and y. In other words, use variables that apply to the direct variation problem being solved.