Posted by **Anonymous** on Thursday, October 7, 2010 at 8:02pm.

An open box contains 80cm^3 and is made from a square piece of tinplate with 3cm squares cut from each of its four corners. Find the dimensions of the original piece of tinplate.

A=80

A=(length)(width)(height)

since length and width are the same, and when the box is folded the height will be 3cm,

80=(w^2)(3)

Since the width has 2 3cm sections cut out of it, I said:

w=x+6

To find x, I tried subbing w=x+6 into my previous equation:

80=((x+6)^2)*3

Which expands as:

(3x^2)+(36x)+28=0

What do I do next? I tried the quadratic formula to get x, but ended up with two negative numbers, which is not a valid solution. Please help me... Was my process wrong?

## Answer this Question

## Related Questions

- math - an open box contains 80cm^3 and is made from a square piece of tinplate ...
- Math - An open box contains 80cm^3 and is made from a square piece of tinplate ...
- Math (Word Problem) - An open gift box is to be made from a square piece of ...
- Calculus - A box with an open top is to be made from a square piece of cardboard...
- math grade 12 - A open-topped box can be created by cutting congruent squares ...
- math - a box is to be made by cutting out the corners of a square piece of ...
- Math - a rectangular piece of cardboard is twice as long as it is wide . from ...
- Math - An open-topped box can be created by cutting congruent squares from each ...
- algebra 2 - you can make an open box from a piece of flat cardboard. First cut ...
- Pre-calc - Congruent squares are cut from the corners of a 20 in. square piece ...

More Related Questions