Rewrite the equation as .

Multiply both sides of the equation by .

Simplify .

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Apply the distributive property.

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Divide each term by and simplify.

Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Rewrite the equation as .

Multiply both sides of the equation by .

Simplify .

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Move all terms containing to the left side of the equation.

Subtract from both sides of the equation.

Subtract from .

Since , the equation will always be true.

Always true

Always true

Solve in Terms of the Arbitrary Variable r a=1/3f(r+k)