Replace with .

Interchange the variables.

Rewrite the equation as .

Add to both sides of the equation.

Divide each term by and simplify.

Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Divide by .

Replace the with to show the final answer.

Set up the composite result function.

Evaluate by substituting in the value of into .

Cancel the common factor of and .

Factor out of .

Factor out of .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Divide by .

Combine the opposite terms in .

Add and .

Add and .

Since , is the inverse of .

Find the Inverse Function f(x)=3x-9