Work Step by Step
If y varies directly with x, then every point on the table should have the same value for y/x. If y/x has the same value at every point, then it will be direct variation, and y/x will be the constant of variation. Thus, we obtain: $ 2.25/-3=-.75 \\\\ -.75/1= -.75 \\\\ -3/4 = -.75$ It is direct variation, where $k=-.75$. Thus, we substitute k to get the equation: $y=-.75x$.