Please help with explanation!

A box is to be made out of a 6 cm by 18 cm piece of cardboard. Squares of side length @ cm will be cut out of each corner, and then the ends and sides will be folded up to form a box with an open top. (a) Express the volume 1 of the box as a function of . V = cm3 (b) Give the domain of V in interval notation. (Use the fact that length, width and volume must be positive.) (c) Find the length L, width WI, and height # of the resulting box that maximizes the volume. (Assume that W