Is it possible to isolate x in the following: f(x) = -4 +2x / 5 + x? If so, how?

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- Sep 23rd 2011, 12:38 PMDmiller93Isolating x?
Is it possible to isolate x in the following: f(x) = -4 +2x / 5 + x? If so, how?

- Sep 23rd 2011, 12:42 PMPlatoRe: Isolating x?
- Sep 23rd 2011, 12:43 PMDmiller93Re: Isolating x?
Yes, it's the same.

- Sep 23rd 2011, 12:45 PMPlatoRe: Isolating x?
- Sep 23rd 2011, 12:47 PMDmiller93Re: Isolating x?
Sorry, could you clarify? I'm not quite sure how to go about doing that.

- Sep 23rd 2011, 01:53 PMSironRe: Isolating x?
Rewrite:

$\displaystyle y=\frac{-4+2x}{5+x}$

$\displaystyle \Leftrightarrow y(5+x)=-4+2x$

$\displaystyle \Leftrightarrow 5y+yx=-4+2x$

$\displaystyle \Leftrightarrow 2x-yx=5y+4$

$\displaystyle \Leftrightarrow x(2-y)=5y+4$

$\displaystyle \Leftrightarrow x=...$