I AM SO CONFUSED! Please Please help but explain the answer! I have been stuck for so long!
Larry is planning to install a rectangular pool that is 6 feet shorter than it is wide. Larry wants to find its width if its area is 169 square feet. Which equation models this problem?

So I know that the length must equal W - 6, and that the area is 169. But, I only know how to find the width by dividing the area by the length (W = A/L). But I do not know the length. So I am kinda sorta really stuck. You do not need to solve this problem. I just need to know the equation to solve this problem. THANK YOU SO MUCH!!