Re: exponential diophantine equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg62931] Re: [mg62922] exponential diophantine equations*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Thu, 8 Dec 2005 06:25:35 -0500 (EST)*References*: <200512080827.DAA17940@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

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

**References**:**exponential diophantine equations***From:*Andrea <andrea@radargift.com>