Math
posted by Jane .
How do I set this up and solve?
You are planing a rectangular dining pavilion. Its length is 3 times its width x. You want a stone walkway that is 3 ft wide around the pavilion. You have enough stones to cover 396 ft squared and want to use them all in the walkway. What should the dimension of the pavilion be? How can you write a variable expression for the area of the walkway?

l=3w
area walkway: outside area inside area
area walkaway=(l+6)x (w+6)lw
=(3w+6)(w+6)3w^2
solve for w. Then, solve for l 
5w=42

How can you write a variable expression for the area of the walkway