Re: Solve equation with summation?

*To*: mathgroup at smc.vnet.net*Subject*: [mg122992] Re: Solve equation with summation?*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sat, 19 Nov 2011 06:48:31 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <ja5f56$69e$1@smc.vnet.net>

Not with my version $Version "8.0 for Mac OS X x86 (64-bit) (October 5, 2011)" Solve[Sum[Subscript[a, i], {i, 1, n}]/x == 1, x] {{x -> Sum[Subscript[a, i], {i, 1, n}]}} Solve[Sum[Subscript[a, i]/x, {i, 1, n}] == 1, x] {} Bob Hanlon On Fri, Nov 18, 2011 at 7:50 AM, Dr. Wolfgang Hintze <weh at snafu.de> wrote: > Sorry, but with me both expressions (exactly copied from your message) > give the same result. > Regards, > Wolfgang > > "Ivan" <iveney at gmail.com> schrieb im Newsbeitrag > news:ja5f56$69e$1 at smc.vnet.net... >> For a summation like \sum_{i=1}^n a_i/x = 1, >> >> Solve[Sum[Subscript[a, i], {i, 1, n}]/x == 1, x] >> >> gives a correct solution. >> >> However, by putting x into the summation: >> >> Solve[Sum[Subscript[a, i]/x, {i, 1, n}] == 1, x] >> >> >> gives an empty set, why? >>