Monday

April 21, 2014

April 21, 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**

trig please - I have no idea how to do this Find the value of the angle theta in...

Math - Given g(x) = print_coeff(m,1)x print_const(b), find g(print_coeff(n,1)a) ...

English - Hi for my english class, we have to make an invention using cheap ...

English - Hi for my english class, we have to make an invention using cheap ...

algebra I - Please help I have no idea where to start. Solve for h 5h + 5+ 4h = ...

the big idea of energy - i have to do an assesment about sound. i have to ...

Math(Please help) - Find the real solutions of each equation. 1) 1 / (x+6)^2 = 1...

please help me please!!! Math - Find a6 for an arithmetic sequence where a1=3x+1...

math - i have a test coming up and i have no idea how to do rotations on a ...

Math(Please help) - If (e^x)^-2 X (e^x)^2 X e^x = 1/e^2 find x? I have no idea ...