<|system|>
What is the sum of all values of $x$ for which the expression $\frac{x-3}{x^2-10x+16}$ is undefined?</s>.
<|user|>
Can you answer based on context?
<|assistant|>
The given expression is undefined when the denominator equals zero. This occurs when $x^2-10x+16=0$. We use the fact that the sum of the roots of a quadratic equation $ax^2+bx+c = 0$ is given by $-b/a$, so we see that the sum of the solutions to this equation must be $-(-10)/1=10$.