Re: bag of marbles question 5th grade HELP!

Thanks for the help...I need to brush up on my algebra now..

"Jack Richey" <jerichey@[EMAIL PROTECTED]
> wrote in message 
news:rhMLj.7908$2g1.7447@[EMAIL PROTECTED]
>
>
> Consider:
>
> R= number of red marbles
>
> B= number of black marbles
>
> B = R + 18
>
> 0.45(B + R) = R
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>
>
> 0.45(R + 18 + R) = R
>
> 0.45(2R + 18) = R
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> 0.90R + 8.1 = R
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> 8.1 = 0.10R
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> 81 = R
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> B = 81 + 18 = 99
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>
>
> "Marvel" <goh@[EMAIL PROTECTED]
> wrote in message 
> news:42244$47fad5af$45283fd7$2586@[EMAIL PROTECTED]
>> What would the formula be?
>>
>> In a bag of  red and black marbles there are 18 fewer red marbles than 
>> black
>>
>> If 45% of the marbles are red how many marbles are in the bag.
>>
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>