Question 4971
{{{(x-(x+3))/(6/((5/6)-(5x/3)))}}}

Distribute the negative sign in {{{x-(x-3)}}} 
{{{x-x+3}}} 
and combine like terms:
{{{3}}}
find a common denominator to the {{{(5/6)-(5x/3)}}}
{{{(3)/(6/(((5-10x)/6)))}}}
Then invert and multiply:
{{{(3)/6}}} * {{{6/(5-10x)}}}
The sixes cancel, leaving
{{{3/(5-10x)}}}