Re: Adding equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg14406] Re: Adding equations*From*: graciark at ippt.gov.pl (Adam Ciarkowski)*Date*: Sun, 18 Oct 1998 15:10:10 -0400*Organization*: IPPT PAN*References*: <703u1n$hup@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <703u1n$hup at smc.vnet.net>, lwalker701 at earthlink.net says... [...] >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 > > One possible approach: 1. Adding (subtracting, multiplying, dividing) of two equations: In[1]:= Inner[Plus, {a,b}, {c,d}, Equal] Out[1]= a+c==b+d. Replace Plus by Subtract, Times or Divide to obtain the three remaining operations, respectively. 2. Adding the quantity c (subtracting, multiplying, dividing) to each side of the equation a==b: In[2]:= Inner[Plus, {a,b}, {c,c}, Equal] Out[2]= a+c==b+c with the same remark as above, or In[3]:= h[y_][eq_]:=eq+y (* or h[y_][eq_]:=eq*y or h[y_][eq_]:=eq/y *) In[4]:= Map[ h[c], Equal[a,b]] Out[4]= a+c==b+c But is it more elegant than the "natural" approach???... Adam ........ (remove gr from my e-mail address)