why does it still running?!

*To*: mathgroup at smc.vnet.net*Subject*: [mg113139] why does it still running?!*From*: olfa <olfa.mraihi at yahoo.fr>*Date*: Fri, 15 Oct 2010 13:50:08 -0400 (EDT)

Hi Mathematica community, why Mathematica still running and so can't give me a solution for this system Reduce[ ((1 - a)*x - b)/a^(i/1) == ((1 - a)*y - b)/a^(j/1) && j == 10,{y}, Backsubstitution -> True] Thank you very much.