8. Given $|x+3|+|x-5|<a$ where the solution for $x$ is non-empty, then the range of values for $a$ 

is
8. Since $|x+3|+|x-5|$ represents the sum of the distances from point $A$ to -3 and 5 on the number line, $|x+3|+|x-5| \geqslant 8$. Therefore, $a \in(8,+\infty)$.