Respuesta :

Answer:

13 x 3 ft

Step-by-step explanation:

RECTANGULAR deck

L x W = 39 ft^2

(w+10)  x w = 39

w^2 + 10w - 39 = 0

(w-3)(w+13) = 0        w = 3    or  -13 (throw out)

w = 3    then l = 10 +3 = 13