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Kris

Guest

Finding the variable in an algebra equation. Please help

Hi there, Newbie here,

In this Equation:   

&

must be a positive integer.

How do I find possible values for B easily if I know A?

(Oh and (6B-5) is meant to be a denominator under (A-B) if that's not clear.)

I am a non-maths person but have come up with this equation for some work I'm doing but I have no idea how to work it out!

Would be great if you could help, thanks guys!

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Finding the variable in an algebra equation. Please help

If

is a positive integer, then

so you can divide the equation above all through by

.

This is true for all values of

(except

). Hence, let

So if you know

, and what the positive integer

must be, you can find

as above.

Kris

Guest

Re: Finding the variable in an algebra equation. Please help

Hi JaneFairfax,

Thanks very much for taking the time to look at my question
The solution to B is great, that's what I was looking for.

But what I'm not sure about, (maybe because I'm not that great at reading maths) is that it seems like you are saying if I want to solve for B
I need to know both what A is and what the positive integer of (A-B)/(6B-5) must be?

But say we make A=16 then 

then 'n' can only be 1 or 2 and therefore B = 2 or B= 3. Any higher value on 'n' would not make B a positve integer?

So I guess my question is, isn't it possible to find out the 1 or 2 values for B simply by knowing what A is?
Do I have to work out the possible values of 'n' when A=16 by manually substituting them into

one by one or is there an equation that will tell me what 'n' must be because other values of 'n' would not make B a positve integer ?

I don't know if that made any sense at all?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Finding the variable in an algebra equation. Please help

OK, I need some help here. Kris' problem is an identity, the RHS reduces to A. Does that matter?

B=1 and A>B will satisfy the criteria that

Last edited by bobbym (2009-05-01 00:04:39)

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