Re: why does it still running?!

*To*: mathgroup at smc.vnet.net*Subject*: [mg113162] Re: why does it still running?!*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sat, 16 Oct 2010 13:10:27 -0400 (EDT)*Reply-to*: hanlonr at cox.net

Works fine on my system $Version "7.0 for Mac OS X x86 (64-bit) (February 19, 2009)" eqns = ((1 - a)*x - b)/a^(i/1) == ((1 - a)*y - b)/a^(j/1) && j == 10; Timing[soln = {Reduce[eqns, {y}, Backsubstitution -> True] // ToRules}] {0.312331, {{j -> 10, a -> 1, b -> 0}, {j -> 10, y -> -((a^-i (-a^10 b + a^i b + a^10 x - a^11 x))/(-1 + a))}, {j -> 10, a -> 1}}} eqns /. soln // Simplify {True, True, True} Bob Hanlon ---- olfa <olfa.mraihi at yahoo.fr> wrote: ============= 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.