Answer:
Step-by-step explanation:
Regardless of how many hours the plumber works, you have to pay $50 for him to even walk into your house. That's non-negotiable. If he charges $40 per hour, then the amount you pay him obviously depends upon the number of hours he works. The variable is x and it represents the number of hours the plumber works. The cost function for hiring this plumber is
y = 40x + 50
That means that $50 is paid even if the plumber does no work at all. If he does an hour's worth of work, x will be replaced by 1, and the fee he will charge is 40 + 50 = 90. If he works 2 hours, x will be replaced by 2, the fee he will charge is 80 + 50 = 130. Etc. Above is the cost function you need to answer this question.
