SOLUTION: large plywood box has a volume of 768 ft3. Its length is 16 ft greater than its height, and its width is 4 ft less than its height. What are the dimensions of the box

Algebra.Com
Question 706395: large plywood box has a volume of 768 ft3. Its length is 16 ft greater than its height, and its width is 4 ft less than its height. What are the dimensions of the box
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
large plywood box has a volume of 768 ft3.
L * W * h = 768
:
Its length is 16 ft greater than its height,
L = (h+16)
:
and its width is 4 ft less than its height.
W = (h-4)
:
(h+16)*(h-4)* h = 768
FOIL
(h^2 - 4h + 16h - 64) * h = 768
(h^2 + 12h - 64) * h = 768
h^3 + 12h^2 - 64h - 768 = 0
We can group factor this
h^2(h+12) - 64(h+12)
Factor out (h+12)
(h+12)(h^2-64) = 0
we are only interested in the positive solution
h^2 = 64
h = 8 ft is the height
then
L = 24, W = 4 ft
:
Check: 24 * 4 * 8 = 768





RELATED QUESTIONS

A large plywood box has a volume of 12 ft3. Its length is 4 ft greater than its height,... (answered by DrBeeee)
A large plywood box has a volume of 240 ft^3. Its length is 16 ft greater than its... (answered by ptaylor)
A large plywood box has a volume of 1008 ft^3. Its length is 16 ft greater than its... (answered by josgarithmetic)
A large plywood box has a volume of 180 ft ( square). Its length is 9 ft greater than its (answered by Nate)
A large plywood box has a volume of 240 ft3. Its length is 16 ft greater than its height, (answered by stanbon)
A large plywood box has a volume of 1440 ft3. Its length is 18 ft greater than its... (answered by harpazo)
Please help me with this word problem: A large plywood box has a volume of 72 ft3. Its... (answered by ankor@dixie-net.com)
I need help with the following word problem: A large plywood box has a volume of 324 ft3. (answered by ankor@dixie-net.com,nerdybill)
The width of a rectangular box is four times its height, and its height is 2 feet more... (answered by macston)