Question 180216
Find all x for which  x^3-x^2-x+1 /x^3-x^2+x-1 = 0.
----
Multiply both sides by the denominator to get:

x^3-x^2-x+1 = 0

Factor to get:
(x^2)(x-1) - (x-1) = 0

Factor again:

(x-1)(x^2-1) = 0

Factor again:
(x-1)(x-1)(x+1) = 0

Solutions: x = 1, or x = -1 
------------------
But x=1 is extraneous as it makes the original denominator = 0
---------
Only solution: x = -1
==========================
Cheers,
Stan H.