For this case we have the following function:
g (x) = (x-1) / (x ^ 2-1)
Rewriting we have:
g (x) = (x-1) / ((x + 1) * (x-1))
Canceling similar terms the function is:
g (x) = 1 / (x + 1)
We evaluate the value of x where the denominator is not defined:
x + 1 = 0
x = -1
Answer:
the correct value of x where the hole is located is:
x = -1