Orlando harvested 5/10 of the crop in the morning. later he harvested 1/7 of the crop. how much more was harvested in the morning?

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Is this a polynomial function? i need to know asap

Ineed with math stuff it involves graphs