# Precalculus Examples

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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.

Solve the equation for , the constant of variation.

Replace the variables and with the actual values.

Dividing two negative values results in a positive value.

Use the direct variation model to create the equation.

Substitute the value of into the direct variation model.

Simplify the result to find the direct variation equation.