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October 31st, 2013, 09:12 AM   #1
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Algebra problem

I want to make B the subject, but i don't know how to. Please may someone tell me how it's done?


Code:
(A-B)/B = C
Thanks for any help
Rob
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October 31st, 2013, 09:16 AM   #2
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Re: Algebra problem

(A - B)/B = C
A/B - 1 = C
A/B = C + 1
A = B(C + 1)
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October 31st, 2013, 09:19 AM   #3
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Re: Algebra problem

Quote:
Originally Posted by greg1313
(A - B)/B = C
A/B - 1 = C
A/B = C + 1
A = B(C + 1)

Hi,

Thanks for that. I originally made my original post wrong. I'm actually looking for B, not A.

Although, i have to ask, how did you get the -1 on your second line. I'm puzzled by how this has happened. Please may you explain?
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October 31st, 2013, 09:22 AM   #4
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Re: Algebra problem

(A - B)/B = A/B - B/B = A/B - 1
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October 31st, 2013, 09:26 AM   #5
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Re: Algebra problem

Quote:
Originally Posted by greg1313
(A - B)/B = A/B - B/B = A/B - 1
Thank you.

And with that explanation, i am also able to get the B that i'm looking for.
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October 31st, 2013, 10:47 AM   #6
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Re: Algebra problem

Quote:
Originally Posted by Shocker
(A-B)/B = C
You can also start with cross-multiplication (example: if a/b = x/y, then ay = bx):
A - B = BC
BC + B = A
B(C + 1) = A
B = A / (C + 1)
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