Question 55917
:
{{{(3x^2 - 9x+6)/(10-5x)}}} = {{{(3(x^2 - 3x + 2))/(5(2 - x))}}} = {{{(3(x - 2)(x - 1))/(5(2 - x))}}}
:
Take the expression 5(2 - x); -5(x - 2) is essentially the same thing replace it with that then cancel:
:  
{{{(3(x - 2)(x - 1))/(-5(x-2))}}} = {{{((3(x - 1))/-5)}}} = {{{-((3(x - 1))/5)}}}