SOLUTION: I think this is a basic question. But it has been 10 years since I had any algebra and I have to take a placement course for college courses. Here is my problem: "if the total cost
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Question 1042637: I think this is a basic question. But it has been 10 years since I had any algebra and I have to take a placement course for college courses. Here is my problem: "if the total cost of x apples is b cents, what is a general formula for the cost, in cents, of y apples?"
I believe I know the answer to this problem, but I need help in understanding why this is the answer. I can get to "by/x" , but I don't remember why I am going through these motions. Is there a law or property that is involved in this problem? Found 2 solutions by josmiceli, ikleyn:Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! The "rate" the apples are selling at is:
{ b cents ] / [ x apples ], or cents/apples
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If you multiply the "rate" by the number of apples
You get the cost of that many apples, so =
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[ cent / apples ] x [ apples ] = [ cents ]
so, the dimensions make sense
You can put this solution on YOUR website! .
if the total cost of x apples is b cents, what is a general formula for the cost, in cents, of y apples?
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1. If "x" apples cost b cents, then one apple costs cents.
Agree?
Now, if one apple costs cents, then "y" apples cost cents.
Did you get it?
2. Proportions.
If "z" is the cost of "y" apples, then you have this proportion
= .
Each side is the price of one single apple.
In proportion, a mean term is the product of the two extreme terms divided by the other mean term.
It gives you
z = .
Exactly the same as in the first approach.
On proportions, see the lesson
- Proportions
in this site.
