I would love some help please and thank you!

11. Find the absolute maximum and absolute minimum values of x) 2 33 + 123 on the closed interwl [3,5]. 12. A man wants to make an opentopped box out of a rectangular sheet of cardboard that is 24 cm wide and 45 cm long. He plans to cut equal squares out of each corner of the sheet and then bend up the edges to form the sides of the box. If the box is to have the greatest possible volume then what should its dimensions be