Question 644439
Volume(V) of a box=Length(L)*Width(W)*Height(H) or V=LWH
Let H=height of the box
Then L=H+16
And W=H-1

Sooooo:
V=240 ft^3=(H+16)*(H-1)*H expanding, we get:
H^3+15H^2-16H-240=0   cubic in standard form and we can factor by grouping
(H^3+15H^2)-16(H+15)=0
H^2(H+15)-16(H+15)=0
(H+15)(H^2-16)=0
(H+15)(H-4)(H+4)=0  so:
H=-15 &
H=-4 &
H=+4----------------------answer

CK
V=240=4*20*3=240
240=240

Hope this helps---ptaylor