A plumber charges $45 for a house call plus $25 for each hour worked.Let h represent the number of h

A plumber charges $45 for a house call plus $25 for each hour worked.Let h represent the number of hours worked. Write the expression that shows how much a plumber charges for a job. Then find how much the plumbers charges for a job lasting 4 hours

Set up the cost function C(h) where h is the number of hours:
C(h) = Hours worked * hourly rate + house call fee
C(h) = 25h + 45 <-- This is the expression for how much the plumber charges for a job

Now determine how much the plumber charges for a job lasting 4 hours
We want C(4)
C(4) = 25(4) + 45
C(4) = 100 + 45
C(4) = $145