198k views
2 votes
a plumber charged $70 for the first 30 minutes of each house call plus $4 for each additional minute he works. if he charges hayden $122 for the house visit how long did the plumber work

1 Answer

4 votes

Answer:

The plumber worked for 43 minutes.

Explanation:

A plumber charged $70 for the first 30 minutes of each house call plus $4 for each additional minute he works.

Now, the total amount to be paid to the plumber C(x) as a function of x number of minutes that he works can be modeled by the equation

C(x) = 70 for x ≤ 30 minutes and C(x) = 70 + (x - 30)4 for x > 30 minutes.

Now, the plumber charges Hayden $122 for the house visit. In that case, x must be greater than 30 minutes.

So, we can write

122 = 70 + (x - 30)4

⇒ 122 = 70 + 4x - 120

⇒ 4x = 172

x = 43 minutes.

Therefore, the plumber worked for 43 minutes. (Answer)

User Jonathan Crowe
by
8.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories