Find the sum of all values of $x$ for which the expression $\frac{x-3}{x^2-10x+16}$ is undefined.

Answer 1

The given expression is undefined when the denominator is equal to zero. Thus, we need to find the solutions to the equation $x^2-10x+16=0$. Factoring, we see that $(x-8)(x-2)=0$, so the solutions are $x=8$ and $x=2$. The sum of these solutions is $\boxed{10}$.