Which of the following equations could be used to find the appropriate value of the car after t years when 0 ≤ t ≤5 ?

[eddy2017]

hi there dear tutors:
the graph represents the change in rate of a $30,000 car over 5 years. Which of the following equations could be used to find the appropriate value of the car after t years when 0 ≤ t ≤5 ?

i have to choose the right answer

the equation given as correct is y= -6000t + 30000

but there’s no explanation whatsoever of what steps or strategy led to the solution and i don't have the slightest idea about how to begin this.

Can you help, and please tell me if there is any video that I can watch dealing with this type of problems.

so appreciative of your help like always!
i think i have not told you my teachers on the forum, but i am not attending a regular school. i have finished my bachelor except for math that i took as a separate subject cos i struggle there.
perhaps you're wondering why i don't ask my teachers or why i do not refer to my textbook. i think you should know this. I'm prepping on my own with your help only and videos and sites on the www.

 

[Dr.Peterson]

hi there dear tutors:
the graph represents the change in rate of a $30,000 car over 5 years. Which of the following equations could be used to find the appropriate value of the car after t years when 0 ≤ t ≤5 ?

i have to choose the right answer

the equation given as correct is y= -6000t + 30000

but there’s no explanation whatsoever of what steps or strategy led to the solution and i don't have the slightest idea about how to begin this.

It seems that we need to see the graph in order to help. May we?

 

[eddy2017]

thanks, Dr Peterson. i am attaching it.

 

[eddy2017]

somehow it uploaded the wrong way, sorry about that.
i just want to say this: forget about the given solution. i have seen sometimes that the solution is not right.
help learn how to approach a problem like that.

 

[Dr.Peterson]

If you're studying linear equations, then just skip this problem entirely! That is not the graph of a linear equation, but either piecewise linear or exponential. Not only is the answer wrong, but it's the wrong question for you.

On the other hand, if either of my descriptions of the graph sounds familiar to you from what you are studying, then tell me what you learned about them. And I'd like to see the other choices given, at least, to make sure what the problem is really asking.

I've probably said this before, but if you're prepping for a math course, using random websites is not a good way to do it. You need a consistent source, either the textbook used in the course you're studying for, or some single online course. At the very least, wherever this problem came from should be abandoned. Even the wording of the problem ("change in rate"???) is bad.

 

[eddy2017]

View attachment 28359

If you're studying linear equations, then just skip this problem entirely! That is not the graph of a linear equation, but either piecewise linear or exponential. Not only is the answer wrong, but it's the wrong question for you.

On the other hand, if either of my descriptions of the graph sounds familiar to you from what you are studying, then tell me what you learned about them. And I'd like to see the other choices given, at least, to make sure what the problem is really asking.

I've probably said this before, but if you're prepping for a math course, using random websites is not a good way to do it. You need a consistent source, either the textbook used in the course you're studying for, or some single online course. At the very least, wherever this problem came from should be abandoned. Even the wording of the problem ("change in rate"???) is bad.

okay, Dr Peterson, i had doubts about it too cos another friend told me it had problems too. he told me the function does not fit 100% whatever that means.
it is not like i am studying randomly. i have a guide of skills i need to get down. Basically skills learned in grades 7 to 12.
i'm working on those from 7th to 9th now .
thanks a lot. i will post a better exercise.

 

[HallsofIvy]

It should be obvious that "Y= -6000t+ 30000" cannot be the equation for that graph because when t= 5, Y= 0 but in the graph Y is NOT 0.