A boy in the school's metal shop wants to make a tray out of rectangular pieces of iron which is 4 inches longer than it is wide. The boy cuts out a 2-inch square from each of the four corners and folds the sides up to form the tray. The volume of the tray is 280 cubic inches. What are the dimensions of the piece of iron?

Let x, y .z be the length, wiodth and height of the nox.

x=4+y.

height =x-4.

(x-4)(y-4)*z=280.

xyz=280.

(x-4)(x-8)*2=280.

(x-4)(x-8)=140.

x^2-12x+32-140=0.

x^2-12x-108=0.

By solving above quadartic x=18,-6.

take only +ve value.

x=18in.

Diem nsions of the box are (18-4) x (18-8)x2.

=14 x 10 x2=