Re: [newb] simple equation substitutions

*To*: mathgroup at smc.vnet.net*Subject*: [mg128545] Re: [newb] simple equation substitutions*From*: "Nasser M. Abbasi" <nma at 12000.org>*Date*: Fri, 2 Nov 2012 00:44:46 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <k6t7qk$1mi$1@smc.vnet.net>*Reply-to*: nma at 12000.org

On 11/1/2012 2:19 AM, Neal Becker wrote: > {y == x + 2, x == 7} > > Solve[%, y] > > -> {} > > What I expected to happen is have x->7 applied to y == x+2. > > My real plan is to develop a list of (a lot more complicated) >expressions that will have repeated substitutions applied. > > Why didn't the above work and/or what should I do instead? > Solve wants you to list _all_ the variables. ----------------------- In[4]:= {y==x+2,x==7}; Solve[%,{y,x}] Out[5]= {{y->9,x->7}} ------------------------ --Nasser