Question 718032
{{{(2x(x+6)^4 - x^2(4)(x+6)^3)/(x+6)^8}}}
By factorisation ,
={{{((2x(x+6)^3)*(x+6)-2x)/((x+6)^8)}}}
if you time the 1st bracket you will get the equation of your question,
then cancle out the common factor,which is (x+6)^3
={{{((2x(x+6)^3)*(x+6)-2x)/((x+6)^3*(x+6)^5)}}}
you will get 
   {{{(2x((x+6)-2x))/((x+6)^5)}}}