Trey mechanic will fix Trey's car at a rate of $20 per hour, plus $400 for the cost of a part. Trey's neighbor already has the needed part and will fix the car for only $70 per hour. For how many hours will the cost of having the car fixed by either person be the same?

8 hours.

Step-by-step explanation:

let x represent number of hours.

We have been given that Trey mechanic will fix Trey's car at a rate of $20 per hour, plus $400 for the cost of a part.

So total cost of repairing a car for x hours by Trey mechanic would be .

We are also told that the neighbor has the needed part and will fix the car for only $70 per hour. So total cost of repairing a car for x hours by neighbor would be .

To find the number of hours, when the cost of fixing the car by either person will be equal, we need to equate both expressions as:

Let us solve for x.

Therefore, after 8 hours the cost of having the car fixed by either person will be the same.

part a

x     y

0     8

1     7.5

2     7

3     6.5

4     6

5     5.5  

for every hour i deducted .5 inches from the length of the candle

part b

it is a function because for every x value there is only one y value

part   c

for every x value there is only one y value

x       y

0       8

1       7.6

2       7.2

3       6.8

step-by-step explanation: