Question

What are the excluded values and how do you simplify the rational expression `(2r-12)/(r^2-36)`?

Answer 1

If we factor, we see

`(2(r - 6))/((r - 6)(r + 6))`

`2/(r + 6)`

We cannot have `r = +-6` because it would make the expression undefined.

Hopefully this helps!