How to work it out .u show me plis

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

Jonathan puts $400 in a bank account. each year the account earns 6% simple interest. how much interest will be earned in 5 years?

Aline passes through the points (5,4) and (2.1). part a.) what is the slope of the line that passes through these points? show work. part b.) what is the equation of the line that passes through these points. show work. part c.) where does the line intercept on the x& y axis? show work