Question

The dimensions in inches of a shipping box at UHAUL can be expressed as width x, length x+5, and height 3x-1. The volume is about 7.6 ft^3. Find the dimensions of the box in inches. Round to the nearest inch.

Answer 1

The volume of the box is the product of the width, length, and height.
Can you write it in terms of x ?

Answer 2

??

Answer 3

I'll right it in math terms so you can understand better
Volume = width * length * height
Volume = 7.6
Therefor:
width * length * height = 7.6
Replace the width, length, and height with their respective values to get an equation that you can solve for x.

Answer 4

write*

Answer 5

ok, I got 3x^2+14x-5 so how do I divide this from 7.6ft^3?

Answer 6

Are sure about 3x^2+14x-5 ?
Should be 3-dimentional..

Answer 7

Volume = x(x+5)(3x-1)
So x(x+5)(3x-1) = 7.6
Distribute and then solve for x.

Answer 8

oh yeah i didn't multiply the x, do you distribute the x to (x+5) only and then multiply with (3x-1)

Answer 9

Yeah whichever way you choose will get you the same thing ;]

Answer 10

so would it be 3x^3+4x^2-5x?

Answer 11

oh yeah my bad

Answer 12

We have 3x^3 + 14x^2 - 5x = 7.6
So 3x^3 + 14x^2 - 5x - 7.6 = 0
Now we just solve for x

Answer 13

how do I do that?

Answer 14

We need to find a way to factor it..

Answer 15

sorry, I don't know how, lol

Answer 16

I put it on wolfram and this is what I got https://www.wolframalpha.com/input/?i=solve++3x^3+%2B+14x^2+-+5x+-+7.6+%3D+0
Are you sure about the data ?

Answer 17

Normally it should be easier to factorize.

Answer 18

Oh my bad !!!
I forgot to convert to inches !!

Answer 19

7.6 ft^3 = ? in^3

Answer 20

I got lost with the factoring

Answer 21

Don't worry about it.
7.6 ft^3 = 13132.8 in^3
So the equation would be 3x^3 + 14x^2 - 5x - 13132.8 = 0
Even here we can't solve it manually...
But using a computer we get x=14.972.
Meaning:
width = x = 14.972 inches
length = x+5 = 19.972 inches
...

Answer 22

ok thanks