A box shaped like a rectangular prism has a height of 17 in and a volume of 2,720 in³ The length is 4 inches greater than twice the width. What is the width of the box?

Question

radar · Answer

Volume V= length(l) X width (w) X height (h)
V=lwh
2720 cu in. =17 X w X (2w+4)
2720 =17w(2w+4)=34w^2+68w=2760

anonymous · Answer

...? r u sure, the answers I got are a lot different, 
–10 in
8 in
20 in
40 in
One of those... *confusedd*

radar · Answer

Typo change the 2760 to 2720

anonymous · Answer

Okay, okay, lol, thanks!!

anonymous · Answer

It's 8!!! :) I think.. lol

radar · Answer

$$34w ^{2}+68w-2720=0$$You want to solve for w.  Divide the equation by 34 getting:$$w ^{2}+2w-80=0$$ This factors quite nicely:
(w+10)(w-8)=0
w=8 as negative value for w would be inappropriate.
w=8
l=20

radar · Answer

Yes you beat me to it, great and good luck with your studies.

anonymous · Answer

Thanks you!!:)