Formula Question

You're right!    Here's an explanation:

perimeter of a rectangle  =  length + length + width + width 

P  =  L + L + W + W

P  =  2L + 2W

                                 To solve this equation for  L , subtract  2W  from both sides.

P - 2W  =  2L

                                 Divide both sides of the equation by  2 .

(1/2)(P - 2W)  =  L

P/2 - W  =  L

L  =  P/2 - W             This is a formula just like the quadratic formula is a formula.