An electrician charges a set fee of $50 for every house call and then charges an additional hourly rate. One day, the electrician earned a total of $400 for a 5 hour job. Write an equation for C, in terms of t, representing the total cost of the electrician's services if the electrician spends t hours at the house working.

1 answer

The total cost C of the electrician's services can be represented by the equation:

C = 50 + t * hourly rate

Since the electrician earned $400 for a 5-hour job, we can substitute these values into the equation:

400 = 50 + 5 * hourly rate

Simplifying the equation, we have:

400 - 50 = 5 * hourly rate

350 = 5 * hourly rate

Dividing both sides by 5, we find:

hourly rate = 350 / 5 = 70

Therefore, the equation for C, in terms of t, is:

C = 50 + 70t