Answer:
.
Step-by-step explanation:
Let C represent total daily charges in dollars and t represent time in hours.
We have been given that a plumber charges $50 for a service call plus $80 per hour.
The amount charged for t hours would be
.
The total amount charged for t hours would be
.
We are also told that plumber spends no longer than 8 hours a day at any one site, this means that time t have a restriction as:

Therefore, our required cost function would be
.
Just add 4 on both sides then divide both sides by 4 and then you’ll get your answer. I hope that helps!
B is the answers I think so
Answer:
4.2 laps
Step-by-step explanation:
because 4 laps is 1600+ the 80 which is a 1/5 of 400 causing it to be .2