Help with a continuity problem!

Hey there, I need some help with a continuity question! I am unsure how to tackle a question like this an could use some assistance.

Let f(x)= { (25-x^2)/ (2(x+5)) if x cannot = -5

= { 2k +3 if x=-5

For what value of k will f be continuous on the real number set (negative infinity, infinity) ??

Where do i even begin?

I realize the first function is equal to (-x+5)/2 but i am unsure of what to do with the 'k'!

Re: Help with a continuity problem!

If $\displaystyle f(x) = \frac{25-x^{2}}{2\cdot (x+5)}$,

And if $\displaystyle g(x) = \frac{5-x}{2}$,

How does he Domain of f(x) differ from the Domain of g(x)?

How does f(x) compare to g(x) everywhere the Domain is the same?

Would f(x) be continuous if your defined f(x) = g(x) for x = -5?