Question 853079
{{{1/(a-b) + 1/(b-a)}}} 
Sorry, I sent this inadvertantly
{{{1/((a-b)) + 1/((b-a))}}}
Change the sign of the 2nd fraction, factor out -1 in the denominator, resulting
{{{1/((a-b)) + 1/(-1(a-b))}}}
now a is positive and b is negative, -1 changes the sign so we have
{{{1/((a-b)) - 1/((a-b))}}} = 0