Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

How to factor a rational

• To: mathgroup at smc.vnet.net
• Subject: [mg78813] How to factor a rational
• From: Steven Siew <siewsk at bp.com>
• Date: Tue, 10 Jul 2007 06:31:16 -0400 (EDT)

I'm trying to factor a rational constant  (4/3) L in equation 1 so
that it looks like equation 2

But I was unable to do so. What would be the correct transformation to
do so?

$ cat file6.out
Mathematica 5.2 for Students: Microsoft Windows Version
Copyright 1988-2005 Wolfram Research, Inc.

In[1]:=
Out[1]= {stdout}

In[2]:= (* Write your mathematica code below *)

In[3]:= eq1 = (4/3)*L*A - (4/3)*L*B == a*k*t

        4 A L   4 B L
Out[3]= ----- - ----- == a k t
          3       3

In[4]:= FullForm[eq1]

Out[4]//FullForm=

>   Equal[Plus[Times[Rational[4, 3], A, L], Times[Rational[-4, 3], B, L]],

>    Times[a, k, t]]

In[5]:= eq2 = (4/3)*L*(A - B) == a*k*t

        4 (A - B) L
Out[5]= ----------- == a k t
             3

In[6]:= FullForm[eq2]

Out[6]//FullForm=

>   Equal[Times[Rational[4, 3], Plus[A, Times[-1, B]], L], Times[a, k, t]]

In[7]:= eq3 = eq1 /. Rational[n_, d_]*(a_)*(b___) + Rational[-n,
d]*(c_)*b -> Ra
tional[n, d]*(a - c)*b

        4 A L   4 B L
Out[7]= ----- - ----- == a k t
          3       3

In[8]:= (* End of mathematica code *)

In[9]:= Quit[];

• Follow-Ups:
  • Re: How to factor a rational
    • From: DrMajorBob <DrMajorBob@bigfoot.com>
  • Re: How to factor a rational
    • From: János <janos.lobb@yale.edu>
  • Re: How to factor a rational
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>