The first thing you want to do is cancel out that pesky extra

*n*(I'm gonna show you my sloppy handwriting for this one since we're dealing with big fractions). That'll get you:

*n*= 5. Well, then

*n*

^{2}is 25, and [

*n*

^{2}- 1] (our denominator) is 24. Answer choice C says

*k*is 24, and that's our answer.

Note that this also could technically have been a BACKSOLVE question, although not the easiest one. If you jumped to the answer choices once you simplified you'd start with C, which says

*k*is 24, and you'd figure out what

*n*would have to be to make [

*n*

^{2}- 1] = 24. So long as your

*n*is an integer (which 5 of course is), you're good to go.