A rectangular piece of cardboard is 11 in. longer than it is wide. Squares 2 in. on a side are to be cut from each corner, and then the sides will be folded up to make an open box with a volume of 84 in3. Find the length and width of the piece of cardboard.
length in
width in

Question

A rectangular piece of cardboard is 11 in. longer than it is wide. Squares 2 in. on a side are to be cut from each corner, and then the sides will be folded up to make an open box with a volume of 84 in3. Find the length and width of the piece of cardboard.
length   	in
width 	in

across · Answer

$$l=w+11$$$$w=l-11$$$$V=lwh=2(l-4)(l-15)=84$$$$l^2-19l+18=0$$$$(l-18)(l-1)=0$$Take l = 18. Then w = 7.