Friday

July 25, 2014

July 25, 2014

Posted by **John** on Tuesday, September 18, 2012 at 8:28am.

A box with an open top is to be constructed by cutting a-inch squares from the corners of a rectangular sheet of tin whose length is twice its width. What size sheet will produce a box having a volume of 420 in^3 when a = 3?

- Math -
**Reiny**, Tuesday, September 18, 2012 at 8:57amYou are cutting out 3-inch squares at the four corners.

Make a diagram.

width of base ---- x inches

length of base --- 2x inches, (you said so)

height of box ---- 3 inches

(x-6)(2x-6)(3) = 420

(x-6)(2x-6) = 140

x^2 - 18x + 36 = 140

2x^2 - 18x - 104 = 0

x = (18 ± √1156)/4

= (18 ± 34)/4

= 13 inches or a negative

so the sheet must have been 13 inches by 26 inches

**Related Questions**

Math - An open box is to be made from a 11 inch by 11 inch piece of cardboad. ...

Calculus - An open top box is made by cutting congruent squares from the corners...

algebra - Open-top box. Thomas is going to make an open-top box by cutting equal...

math - open top rectangular box made from 35 x 35 inch piece of sheet metal by ...

Calculus - an open top box is to be made by cutting congruent squares of side ...

Math - A box with no top is to be constructed from a piece of cardboard whose ...

MATH help - A box with no top is to be constructed from a piece of cardboard ...

Algebra - A box with no top is to be constructed from a piece of cardboard ...

calculus - An open box is to be made out of a 8-inch by 14-inch piece of ...

AFM (MATH) - a) Write an equation to represent the volume of an open box ...