Math Help - parent needs equation help for junior algebra II

HELP ME!
I do not know how to help mey daughter with her "The Cell Phone Dilemma" worksheet which asks her to create an equation offering the following info:

"You are going to buy a new cell phone. You are trying to decide between the ne IPhone 5 or the older model but still quite nice, IPhone 4. The following chart is the data given to you to help you make your decision.

PRICE IPhone4 IPhone5
$100 3000 0
$200 2400 400
$400 1200 1200
$600 0 2000

Write equations algebraically for each situation. You must show your work for this process.

Can someone help expalin to me how to equate an equation with these figures so that I can help my daughter?
Thank you

I believe one needs more information. What is the meaning of the values in the 2nd and 3rd columns?

The first column is "Price" and states:
$100
$200
$400
$600
The second column is quantity available for Iphone4, and states:
3000
2400
1200
0
The third column is quantity for Iphone5, and states:
0
400
1200
2000
Thank you SO very MUCH!

Originally Posted by giagia

The first column is "Price" and states:
$100
$200
$400
$600
The second column is quantity available for Iphone4, and states:
3000
2400
1200
0
The third column is quantity for Iphone5, and states:
0
400
1200
2000
Thank you SO very MUCH!

Could you please post the wording of the problem eactly as on the sheet please.

CB

It says:
"You are going to buy a cell phone. YOu are trying to decide between the new Iphone5 or the older model but still quite new, Iphone 4. The following chart is the data you have to make your decision.
Write equations algebraically for each situation. You must show your work for this process."

There seems to be a linear relationship between price and quantity for each phone.

Seek an equation in the form of y=mx+c where m is the change in quantity per $100 and c is the quantity at $0.

Spoiler:

Iphone 4:
Iphone 5:

But you only need to buy one phone. Why would the "quantity available" (as long as it is larger than 0) affect your decision at all?