Re: factor out a term to cancel in a fraction

*To*: mathgroup at smc.vnet.net*Subject*: [mg98847] Re: factor out a term to cancel in a fraction*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Mon, 20 Apr 2009 05:46:43 -0400 (EDT)*Organization*: Uni Leipzig*References*: <gsh178$o8$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, eqn = p'[t] == (e0 s[t] k1 k2)/(s[t] k1 + k1 Km); and eqn /. a_ == b_ :> a == Cancel[b] or Cancel[eqn] or Simplify[eqn] or FullSimplify[eqn] or eqn /. a_*k1 + b_*k1 :> (a + b)*k1 will do it and it seems difficult to hinder Mathematica to cancel k1. Regards Jens sean_incali at yahoo.com wrote: > Hello group. > > I'm trying to do a little algebra which i can do in my head using > Mathematica. Why? Well, it's neater. > > Consider the following. > > > p'[t] == (e0 s[t] k1 k2 )/ (s[t] k1 + k1 Km) > > Factor out k1 and cancel it to simplify the expression. Why is this so > difficult to accomplish in mathematica? Following does nothing. > > p'[t] == (e0 s[t] k1 k2 )/ (s[t] k1 + k1 Km) // > Assuming[k1 > 0, {Collect[#, k1]}] & > > > Thanks for any info. > > Sean > >