Re: exponential diophantine equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg62949] Re: [mg62922] exponential diophantine equations*From*: Andrea <andrea at radargift.com>*Date*: Fri, 9 Dec 2005 05:10:31 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Dear Andrzej, Oh those signs! I typed +7. Mistake. It should be -7. Andrea At 01:38 AM 12/8/2005, Andrzej Kozlowski wrote: >On 8 Dec 2005, at 17:27, Andrea wrote: > >> >>I'm trying to find out how to use Mathematica to find solutions to >>exponential diophantine equations like the following: >> >> (5x)^2 - 2^k * 3 * (5+k)^2 - 131 * k + 7 = 0. I want to >>obtain >>solutions for x and k. (One solution is x = 31, k = 6, but I didn't >>find >>this using Mathematica!) > >Are you sure you have found a solution? I get: > >In[30]:= >(5x)^2 - 2^k * 3 * (5+k)^2 - 131 * k + 7 /.{x->31,k->6} > >Out[30]= >14 > > >One can certianly try some "educated searches" but before starting it >woudl be better to be sure that this is really the equation you want >to solve! > >Andrzej Kozlowski >