Posted by Nikki on .
An open box is made from a square piece of metal by cutting out a 4 inch square from each corner and turning up the sides. Find the area of the original square if the box is to contain:
A) 16 cubic inches
And
B) 400 cubic inches

Math 
Reiny,
let the piece of metal be x inches by x inches
base of box is (x8) by (x8) , where x
so
4(x8)(x8) = 16
x^2  16x + 64 = 4
(x6)(x10) = 0
x = 6 or x = 10 , but remember x > 8
so the original piece of metal was 10 inches by 10 inches
You try B