Question 605058
{{{(x^3 - x)/(x^3 + 5x^2 - 6x)}}}
Factor and cancel x
{{{x(x^2 - 1)/x(x^2 + 5x - 6)}}} = {{{(x^2 - 1)/(x^2 + 5x - 6)}}}
Factor again, cancel (x-1) 
{{{((x-1)(x+1))/((x+6)(x-1))}}} = {{{(x+1)/(x+6)}}}