Question 969531
#2 again according to the newer description:


{{{(2x)/(9x^2+15)-8/(3x+5)}}}


The goal suggested would seem to perform addition (or subtraction) of rational expressions.


{{{9x^2+15=3(x^2+5)}}}, so you have  {{{(2x)/((3)(3x+5))-8/(3x+5)}}};


{{{(2x)/((3)(3x+5))-(8/(3x+5))(3/3)}}}, typical fraction skill,


{{{2x/(3(3x+5))-8*3/(3(3x+5))}}}


{{{(2x-24)/(3(3x+5))}}}


{{{highlight((2x-24)/(9x^2+5))}}}----------this would be your finished form for #2.


Any restrictions on x?
Yes.
The denominator must be NONZERO.
{{{9x^2+5<>0}}}



Suggestion for #1 is to again, use the fraction skills which you already know.  Your description of what you are starting with is  {{{((x^2-x-6)/(x^2-4))/((x^2-2x+1)/(x^2-1))}}}.


What would you do for {{{(a/b)(c/d)}}}?
Then, what else to simplify, if possible?