Question 855780
NOTES:
So that we do not misunderstand, it is better to write y^2 for {{{y^2}}} .
Computers, math geeks, and many calculators understand that ^ means what follows is an exponent, and that / means divide.
Computers, math geeks, and most calculators understand that
y^2-5y-6/y^2-1 means {{{y2-5y-6/y2-1}}} ,
while {{{(y^2-5y-6)/(y^2-1)}}} should be written as (y^2-5y-6)/(y^2-1) to follow the long internationally accepted conventions/rules on order of operations.
I understand what you meant because I can read minds, but don't try that with your calculator, or you will get exactly what you ask for.
 
{{{(y^2-5y-6)/(y^2-1)=(y+1)(y-6)/((y+1)(y-1))}}}{{{red("=")}}}{{{(y-6)/(y-1)}}}
when {{{y<>-1}}} the expressions on the left of the red equal sign exist, and are equal to the simplified expression on the right, which does exist for {{{x=-1}}} .