Can someone please help me with this homework question? Thank you so much

What is the slope simplify your answer and write it as a proper fraction, improper fraction, or integer

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

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28