Question 746275
the way it is written has no solution, so I'm assuming you mean this:

{{{
(x-a)/(x+a) - (x+a)/(x-a)=7/12
}}}


then...

{{{
((x-a)/(x+a))((x-a)/(x-a)) - ((x+a)/(x-a))((x+a)/(x+a))=7/12
}}}

{{{
((x^2-2*x*a+a^2)-(x^2-2*x*a+a^2))/(x^2-a^2)=7/12
}}}


{{{
(-4*a*x)/(x^2-a^2)=7/12
}}}


{{{
-48*a*x=7(x^2-a^2)
}}}


{{{
7x^2+48*a*x-7a^2=0
}}}

{{{
(7 x-a) (7 a+x)=0
}}}

so x=a/7 or x=-7a but in either case

{{{ x <> -a}}} and {{{x<>0}}}