Answer:
8
Step-by-step explanation:
Assuming the given expresion is:
[tex] \frac{a + 6}{a - 8} [/tex]
Then we have a rational expression with domain a≠8
This means that we can replace 'a' with all real values except a=8.
We obtain this by setting the denominator equal zero and solve for 'a'.
The reason is that, the expression is not defined when the denominator is zero.
Therefore the non-permisible replacement is 8