A company packages candy in a rectangular box with a square base and no internal dividers. The box must have a volume of 216 cm3. Cardboard for the base costs \0.06persquarecentimeter,whilecardboardforthefoursidesandthetopcosts0.02 per square centimeter. Determine the side length x (in centimeters) of the square base that minimizes the total material cost of one box.