Chapter 2 - Functions, Equations, and Graphs - 2-2 Direct Variation - Practice and Problem-Solving Exercises - Page 71: 15

This is not a direct variation equation. ($y$ does not vary directly with $x$).

Direct variation can be represented as $y=kx$, where k is the constant of variation. This equation cannot be represented as $y=kx$ because it has a y-intercept, so this is not a direct variation equation.