Can you help me answer this?

By cutting away an x-by-x square from each corner of a rectangular piece of cardboard and folding up the resulting flaps, a box with no top can be constructed. If the cardboard is 30 inches long by 30 inches wide, determine the value of x that yields the maximum volume of the resulting box. X = inches Use this value of x to compute the maximum volume of the box. Maximum volume of box - cubic inches