Find all values of [tex]c[/tex] such that the limit exists.
[tex]
\lim _{x \rightarrow 1} \frac{x^2+6 x+c}{x-1}
[/tex]
(Give your answer in the form of a comma-separated list. Express numbers in exact form. Use symbolic notation and fractions where needed. Enter DNE if there are no values of [tex]c[/tex] such that the limit exists.)
