1. If the total area is a = 3000 cm² and the width of the poster is x then you know:

2. Cut of the margin:

from the length cut of 12 cm in total and from the width cut of 4 cm in total. The area of the printing part is then:

3. Now calculate the maximum of using derivation.

--------------------------------

You are supposed to know that

Therefore: Traveling time is

Total costs:

Now calculate the maximum of using derivation.