Re: Setting up equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg66038] Re: Setting up equations*From*: dh <dh at metrohm.ch>*Date*: Thu, 27 Apr 2006 04:36:29 -0400 (EDT)*References*: <e2nd3i$33m$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Yaroslav, you could transform your expression into the null polynomial and extract coefficents of x,y,z. E.g.: eq1=5 x + 6 y + 7 z == a x + b y + c z eq2= Subtract @@ eq1 Extracting coefficients: cof= Coefficient[eq2,{x,y,z}] and putting them into an new equation: (# == 0) & /@ cof this yields a list of equation that you may solve by Solve or Reduce Daniel Yaroslav Bulatov wrote: > I'm trying to do things of the form > Solve[5 x + 6 y + 7 z == a x + b y + c z, {a, b, c}] > > But since x,y,z are variables, what I really mean is > Solve[5==a && 6==b && 7==c], so I need to convert to this form > > If I only have one variable, the following does what I need > > LogicalExpand[a*x + b*x^2 + O[x]^3 == 2*x + 3*x^2 + O[x]^3] > > But what to do if I have several variables? >