Mark Clements wrote:

The following problem came up on the Maxima mail-list (translated here into Axiom):

-- solve for x (over the Reals?)

ex := (3/7)^(4*x-5)*(7/3)^(2*x-7)=1

I came up with several overly long solutions (using Fricas 1.0.3):

rule1 := (rule log(7/3)==-log(3/7))

rule1 rhs solve(map(expandLog,map(log,ex)), x).1

-- or, similarly

rule1 rhs solve(expandLog log lhs ex, x).1

rule2 := rule((a/b)^c*(b/a)^d==(a/b)^(c-d))

solve((rule2 lhs ex)=(rhs ex),x)

Can anyone come up with a better solution?

Kindly, Mark Clements.

------------------------------------------------------------------------

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a:=(3/7)*(4*x-5)*(7/3)*(2*x-7)-1
b:=zerosOf(a)

   +--+         +--+
  \|89 + 19, - \|89 + 19
 [---------, -----------]
      8           8
                                Type: List AlgebraicNumber


eval(a,x=b.1)
   0

eval(a,x=b.2)
   0


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