Question 1062161
5*w*(w+17) = 300
w(w+17) = 60
w^2+17w = 60 
add 289/4 to both sides:
w^2+17w+289/4 = 529/4
Write the left hand side as a square:
(w+17/2)^2 = 529/4
Take the square root of both sides:
w+17/2 = 23/2 or w+17/2 = -23/2
w = 3 or w = -20
discard the -20, we are not looking for a negative number.
Let's try 3 (boy, this is a really narrow box!):
width: 3
Length: 3+17 = 20
height: 5
Volume = w*l*h = 3*20*5 = 300 Correct!
:
John