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Re: Form of a linear equation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg53750] Re: [mg53734] Form of a linear equation
  • From: DrBob <drbob at bigfoot.com>
  • Date: Wed, 26 Jan 2005 04:36:34 -0500 (EST)
  • References: <200501251003.FAA14449@smc.vnet.net>
  • Reply-to: drbob at bigfoot.com
  • Sender: owner-wri-mathgroup at wolfram.com

expr = -(4 + 4x + y)/17^(1/2) == (2 + x + y)/2^(1/2);
Collect[Subtract @@ expr, Variables[Subtract @@ expr]] == 0

(-(1/Sqrt[2]) - 4/Sqrt[17])*x +
    (-(1/Sqrt[2]) - 1/Sqrt[17])*
     y - 4/Sqrt[17] - Sqrt[2] == 0

Bobby

On Tue, 25 Jan 2005 05:03:48 -0500 (EST), DJ Craig <spit at djtricities.com> wrote:

> I'm trying to convert this linear equation:
>
> -(4+4x+y) / 17^(1/2) = (2+x+y) / 2^(1/2)
>
> into the form:
>
> (a_)*x + (b_)*y + (c_) = 0
>
> This sounds simple enough, but I can't figure out how to make
> Mathematica do it.  My TI-89 does it automatically, but I need to be
> able to do this like a batch process for a bunch of linear equations.
> Heres the solution the TI-89 gives me:
>
> \!\(\*
> StyleBox[\(\((\(\(-4\)\ \@17\)\/17 - \@2\/2)\)\ x + \((\(-\@17\)\/17
> - \
> \@2\/2)\)\ y - \(3\ \@17\)\/17 - \@2 = 0\),
> FontWeight->"Bold"]\)
>
> Just copy and paste that mess into Mathematica and it will change into
> the equation at the top, but in the form that I want it.
>
> I haven't been using Mathematica for long.  I'm used to my TI-89; I've
> been using it for years.
>
>
>
>



-- 
DrBob at bigfoot.com
www.eclecticdreams.net


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