volume = 2730 what is equation?

[Janie13]

the problem is:

Volume = 2730

2730= (x+3)(2x+1)(x)


i'm lost.......what is formula for finding "x" please?

 

[skeeter]

Re: Area of rectangle equation

expand (multiply out) the right side, rearrange the resulting cubic equation so that it equals 0, solve for x.

what do you know about solving higher order polynomial equations?

 

[Janie13]

Re: Area of rectangle equation

the entire problem reads like this:

the length of a rectangle box is 1 inch more than twice the height of the box, and the width is 3 inches more than the height. if the volume of the box is 2730 cubic inches, find the dimensions of the box.

 

[skeeter]

what do you know about solving cubic equations?

 

[Janie13]

not alot.......i know the answer is x = 10, but i don't know how to show/work the equation. i just figured it my own way.

 

[Janie13]

i got: 2x^3 + 7x^2 + 3x - 2730 = 0

but how do i solve for X ?

 

[skeeter]

ever hear of the rational root theorem?

this link may help ...

http://www.themathpage.com/aPreCalc/factor-theorem.htm

 

[Janie13]

thanks for the link - maybe i can figure it out