I can't figure out how to do this problem

Question

A repair company charges a fixed amount plus an hourly rate for a service call. Suppose it charges $159 for one-hour and $219 for five-hour call. Find a linear function that describes the price of a service call in terms of 𝑥x, the number of hours.

p= 

Answer 1

Start with two-point form

(y - 159) / (x - 1) = (219 - 159) / (5 - 1)