Re: Adding equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg14385] Re: [mg14342] Adding equations*From*: "Kevin J. McCann" <kevinmccann at Home.com>*Date*: Sun, 18 Oct 1998 15:09:52 -0400*Sender*: owner-wri-mathgroup at wolfram.com

eq1 = a == b eq2 = c == d Thread[eq1 + eq2,Equal] a+c==b+d The "Equal" in the Thread is the key. Kevin -----Original Message----- From: Lawrence Walker <lwalker701 at earthlink.net> To: mathgroup at smc.vnet.net Subject: [mg14385] [mg14342] Adding equations >Group: > >I've been trying to add two equations as follows: > >In[4]:= > a==b; >In[5]:= > c==d; >In[6]:= > %4+%5 >Out[6]= > (a==b)+(c==d) > >The result I was looking for is (a+c)==(b+d). The following works but it >seems clumsy. In[7]:= > %4[[1]]+%5[[1]]==%4[[2]]+%5[[2]] Out[7]= > a+c==b+d >Is there a way to elegantly add (sub, mult, div) two equations? Also is >there an elegant way to add (sub, mult, div) an expression to both >sides of an equation? > >Lawrence Walker > >