Answer with explanation: To find the values of x where the f(x) is discontinuous, we have to set the denominator equal to zero, doing this gives:
![\begin{gathered} f(x)=(x^2+10+9)/(x^2-81)\Rightarrow x^2-81=0 \\ x=\sqrt[]{81}=9 \\ x=9 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ffimydu8ojmtrc7apjh924f7lc3zs0w3ii.png)
The f(x) is discontinuous at x = 9, following graph confirms it:
In conclusion, discontinuity is non-removable.