# Precalculus Examples

, ,

When three variable quantities have a constant ratio, their relationship is called a direct variation. It is said that one variable varies directly as the other two vary. 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.

Multiply by to get .

Reduce the expression by cancelling the common factors.

Cancel the common factor.

Rewrite the expression.

Remove parentheses around .

Raise to the power of to get .

Write the equation of variation such that , replacing with the .