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 .

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Replace the with to show the final answer.

Set up the composite result function.

Evaluate by substituting in the value of into .

Simplify terms.

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.

Combine the numerators over the common denominator.

Simplify the numerator.

Add and .

Add and .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Since , is the inverse of .

Find the Inverse 20x-4