Question 68215
   
  {{{((a-b)/(a+b))/((a^2-b^2)/(a^2+2ab+b^2))}}}
  
= {{{((a-b)/(a+b))/((a+b)(a-b)/(a+b)(a+b))}}}  =  {{{((a-b)/(a+b))/(cross((a+b))(a-b)/cross((a+b))(a+b))}}}  =  {{{((a-b)/(a+b))/((a-b)/(a+b))}}}  =  {{{((a-b)/(a+b)) * ((a+b)/(a-b))}}}  =  {{{(cross((a-b))/cross((a+b))) * (cross((a+b))/cross((a-b)))}}}  =  1.  Answer.  Is this clear to you?  All the best.


gsm