# Precalculus Examples

, ,

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

Multiply the numerator by the reciprocal of the denominator.

Step 5

Step 5.1

Multiply by .

Step 5.2

Multiply by .

Step 6

Use the formula to substitute for and for .

Step 7

Step 7.1

Multiply by .

Step 7.2

Multiply by .

Step 7.3

Remove parentheses.

Step 7.4

Simplify .

Step 7.4.1

Multiply by .

Step 7.4.2

Cancel the common factor of .

Step 7.4.2.1

Factor out of .

Step 7.4.2.2

Cancel the common factor.

Step 7.4.2.3

Rewrite the expression.