Question 104097
L=3w
(3w-2)(w-2)+36=3w^2
3w^2-8w+4+36=3w^2 subtract 3w^2 from each side.
-8w+40=0 
-8w=-40 subtract 40 from each side.
w=5 divide each side by -8
L=15
Check:
5*15=75
3*13=39
75-39=36
Ed