Rewrite the equation as .

Multiply both sides of the equation by .

Simplify the left side.

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Simplify .

Cancel the common factor of .

Factor out of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Add to both sides of the equation.

Add and .

Solve for f 40=5/9(f-32)