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'!