Question

A plumber charges $50 to visit a house plus $40 for every

hour of work. Define a variable and write an expression to represent
the total cost of hiring a plumber.

Answer 1

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.