SOLUTION: A open tray is to be made from a 8.5-inch by 12-inch piece of sheet metal by cutting squares of equal size from each corner and bending up the flaps, write a formula for the volume

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A open tray is to be made from a 8.5-inch by 12-inch piece of sheet metal by cutting squares of equal size from each corner and bending up the flaps, write a formula for the volume      Log On


   



Question 623310: A open tray is to be made from a 8.5-inch by 12-inch piece of sheet metal by cutting squares of equal size from each corner and bending up the flaps, write a formula for the volume of the tray as a polynomial function...I think it starts out like this V(x)=4x(12-2x)(8.5-2x) but Im not sure.
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
Except for the 4, your formula is exactly correct. The general formula for volume of this shape (rectangular prism) is:
V = l*w*h
You got the length and width right. But the height is just x, not 4x. So the volume of your tray is:
V(x)=x(12-2x)(8.5-2x)

This is not a polynomial, however. So we need to multiply it out. Distributing the x we get:
V%28x%29=%2812x-2x%5E2%29%288.5-2x%29
Now we use FOIL to multiply the rest:
V%28x%29=12x%2A8.5+%2B+12x%2A%28-2x%29+%2B+%28-2x%5E2%29%2A8.5+%2B+%28-2x%5E2%29%2A%28-2x%29
Simplifying...
V%28x%29=102x+%2B+%28-24x%5E2%29+%2B+%28-17x%5E2%29+%2B+4x%5E3
V%28x%29=102x+%2B+%28-41x%5E2%29+%2B+4x%5E3
Normally we write polynomials in order from highest exponent to lowest:
V%28x%29=4x%5E3+%2B+%28-41x%5E2%29+%2B+102x