I would really appreciate the help guys..:)

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

You receive 15% of the profit from a car wash how much money do you receive from a profit of 300

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18