## boxes volume

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
wkaidy
Posts: 4
Joined: Sat Nov 17, 2012 11:41 pm
Contact:

### boxes volume

havin trouble with this problem... the volume of the larger rectangular box is three times the volume of the smaller rectangular box what is the value of x?

the sides of the large box are as follows l= x=2, w= x=1 h=x all three sides of the small box are x how would i go about solving this? thank you

stapel_eliz
Posts: 1628
Joined: Mon Dec 08, 2008 4:22 pm
Contact:
havin trouble with this problem... the volume of the larger rectangular box is three times the volume of the smaller rectangular box what is the value of x?

the sides of the large box are as follows l= x=2, w= x=1 h=x all three sides of the small box are x how would i go about solving this? thank you
The exercise asks for the value of x, but then you say that the exercise has given you two values for x: x = 2 and x = 1. Also, h = l = w = h. This does not make sense.

Kindly please reply with the exact text of the exercise or, if the above is the exact text, please ask your instructor for a corrected version. Thank you!

wkaidy
Posts: 4
Joined: Sat Nov 17, 2012 11:41 pm
Contact:

### Re: boxes volume

sorry l=x+1 w=x h=X+2

maggiemagnet
Posts: 358
Joined: Mon Dec 08, 2008 12:32 am
Contact:

### Re: boxes volume

sorry l=x+1 w=x h=X+2
I'll guess that "X" is meant to be the same as "x". (This is usually not true in math, so please say if I'm wrong!)

What is the formula for the volume V of a rectangular solid (or box, in this case) with width w, length L, and height h? Plug the expressions they gave you into the formula for the variables. Simplify to get the volume of the larger box. Do the same thing for the smaller box, with w = L = h = x. Then create an equation that says "(large volume) is (three times of)(small volume)". Solve the equation for x.

If you get stuck, please write back showing your work for the steps I gave you. Thanks!

wkaidy
Posts: 4
Joined: Sat Nov 17, 2012 11:41 pm
Contact:

### Re: boxes volume

so i get
3x=(x)(x+2)(x+1)
so 3x= x^2+2x^2+2x and im stuck

maggiemagnet
Posts: 358
Joined: Mon Dec 08, 2008 12:32 am
Contact:

### Re: boxes volume

so i get
3x=(x)(x+2)(x+1)
so 3x= x^2+2x^2+2x and im stuck
Where is the 3x coming from? What does the sum in your second equation relate to? (It's not volume.) What is your simplified expression for the larger volume? What is your simplified expression for the smaller volume? What is your equation that relates the two volume expressions? Thanks!

wkaidy
Posts: 4
Joined: Sat Nov 17, 2012 11:41 pm
Contact:

### Re: boxes volume

I dont fully understand would you mind giving me a run down on how to do this type of problem i have to do a bunch of them and am compleatly lost

maggiemagnet
Posts: 358
Joined: Mon Dec 08, 2008 12:32 am
Contact:

### Re: boxes volume

I dont fully understand would you mind giving me a run down on how to do this type of problem i have to do a bunch of them and am compleatly lost
I did give you a run-down: They gave you expressions for L, w, and h of the big box in terms of x. Plug these into the formula for the volume V of a box with length L, width w, and height h. This gives you an expression for the big volume in terms of x. What expression do you get? They also gave you expressions (all the same one-variable expression) for L, w, and h of the small box in terms of x. What expression do you get? They also gave you a relationship: "(the big volume) is (three times of)(the small volume)". Plug your expressions into the equation, and solve.