Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Since the equation can be written in the form , varies directly with and . The constant of variation, , is .

Find the Constant of Variation -16y=-2x