Re: symbolic evaluation
- To: mathgroup at smc.vnet.net
 - Subject: [mg86982] Re: symbolic evaluation
 - From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
 - Date: Fri, 28 Mar 2008 03:14:37 -0500 (EST)
 - Organization: The Open University, Milton Keynes, UK
 - References: <fsg6n1$j55$1@smc.vnet.net>
 
news.east.cox.net wrote:
> I'm using Mathematica 5.1 I want to evaluate a simple equation 
> symbolically, such as 7x = 14. of course the answer should be x = 14/7. 
> I can't find a clear example on how to do this with a simple equation. 
I am not sure whether the issue is about keeping the rational number 
14/7 in its unsimplified form (Mathematica will simplify it 
automatically to two). If this is the case, you could use HoldForm (at 
least for simple expression). For instance,
In[1]:= Reduce[7 x == HoldForm@14]
Out[1]=
      14
x == --
      7
Otherwise, you can just use Reduce, Solve, or even Simplify as in the 
following examples.
In[2]:= Reduce[7 x == 14]
Out[2]= x == 2
In[3]:= Solve[7 x == 14]
Out[3]= {{x -> 2}}
In[4]:= Simplify[7 x == 14]
Out[4]= x == 2
Regards,
-- 
Jean-Marc