So if your at 0 and you add 9 left but then you go 4 right so you would do 9-4 and then you go left 6 more so you would take the sum of 9-4 which would be 5 and you add 6 so the car would have only traveled 11cm left
Please leave a comment with the choices and I will answer your question. If not I would start with a sun burn as the least and cancer as the most serious.