Please use lower-case letters, such as 'a', instead of upper-case letters for names you devise. (To avoid clashes with built-in Mathematica names, all of which begin with '$' or else an upper-case letter.) Thus you should use for your equation:
x + 1/(1 + r^x) + a == 0
Are r and a supposed to be real, or would complex values be OK? What range of values do you want for r or for a?
What makes you think there is a solution? Have you tried plotting. Look, e.g., at:
On Mar 3, 2013, at 10:58 PM, Norman Polozka <firstname.lastname@example.org> wrote:
> I want to solve such equation by using mathematica, > > Solve[x+1/(1+r^x)+A==0,x] > > But it says it can't solve. Any idea of solving such equations?
--- Murray Eisenberg email@example.com Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2838 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305