failure with solution of trivial exponential equations

[rwst]

From http://ask.sagemath.org/question/26237/why-can-sage-solve-one-log-equation-but-not-another-with-only-different-values/

sage: solve(3 == 586 * (1/5) ^ x, x)
[x == log(586/3)/log(5)]

but:

sage: solve(3 == 586 * (99557/100000) ^ x, x)
[100000^x == 586/3*99557^x]

A solution:
log(3/586) / log(0.99557) = 1188.03958878842

Component: calculus

Issue created by migration from https://trac.sagemath.org/ticket/18006