Sunday

August 31, 2014

August 31, 2014

Posted by **nicole** on Friday, September 13, 2013 at 7:43pm.

- math -
**Steve**, Friday, September 13, 2013 at 7:46pmthis problem has been solved in many of the related questions below, with different numbers. Follow some of them and give it a shot. What do you get?

- math -
**Graham**, Friday, September 13, 2013 at 8:16pmLet the sides you cut out be x centimetres long.

The volume is then:

(30-2x)(21-2x)x = 1080

Expanding:

4 x^3 - 102 x^2 + 630 x - 1080 = 0

Look for common factors:

(x-3)(4x^2 - 90x + 360) = 0

Found one root, solve the quadratic for the other.

**Related Questions**

Pre-Calculus - An open box is to be made from a piece of cardboard 11 in by 17 ...

Math - An open box is made from a square piece of metal by cutting out a 4 inch ...

math - a square sheet of tin 30cm on a side is to be used to make an open - top ...

math - An open-top box is to be constructed from a 6 foot by 8 foot rectangular ...

Calculus (Optimization) - A rectangular piece of cardboard, 8 inches by 14 ...

Math - A manufacturer uses a 28 x 41 metal sheet to construct an open box by ...

math - mr. m has an 8 inch by 11 inch sheet of paper. He created a box by ...

algebra - open box made from 33 x 33 inch sheet of metal by cutting out x-inch ...

algebra - An open-top box is to be constructed from a 6 foot by 8 foot ...

Math - mr. m has an 8 inch by 11 inch sheet of paper. He created a box by ...