# Precalculus Examples

Find the Equation that Relates x and y
,
Step 1
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 , where is the constant of variation.
Step 2
Solve the equation for , the constant of variation.
Step 3
Replace the variables and with the actual values.
Step 4
Use the direct variation model to create the equation.
Step 5
Substitute the value of into the direct variation model.
Step 6
Simplify the result to find the direct variation equation.