Find the Equation that Relates x and y y=18 x=9

When two variable quantities have a constant ratio, their relationship is called a direct variation. It is said that one variable varies directly as the other. The formula for direct variation is ${\displaystyle y=kx}$, where ${\displaystyle k}$ is the constant of variation.

Solve the equation for ${\displaystyle k}$, the constant of variation.

Replace the variables ${\displaystyle x}$ and ${\displaystyle y}$ with the actual values.

Divide ${\displaystyle 18}$ by ${\displaystyle 9}$.

Use the direct variation model to create the equation.

Substitute the value of ${\displaystyle k}$ into the direct variation model.