Respuesta :

w^2 + 70w + 2450 = 8450

w^2 + 70w - 6000 = 0

.

Factoring the left:

(w-50)(w+120) = 0

.

w = {-120, 50}

.

toss out the negative solution:

width is 50 feet

length is 50+70= 120 feet