Question 434008
I'm assuming you mean:
{{{(121-x^2)/(x^2+15x+144)}}}
This is factoring-
{{{((11-x)(11+x))/((x+11)(x+4))}}} Note-if you FOIL these back, you'll see you get the original polynomials.
{{{(11-x)/(x+4)}}} The 11+x cancels with the x+11