<p>Hey, this problem appeared easy at first but I can't seem to get the correct answer (C). Thanks in advance.</p>
<p><a href="http://i.imgur.com/ZOi5z.jpg%5B/url%5D">http://i.imgur.com/ZOi5z.jpg</a></p>
<p>You’ll want to simplify the left side of the equation and then set the numerators and denominators of the resulting fractions equal to each other respectively.</p>
<p>On the left we have n^2/(n)(n-1)(n+1).
Cancel out n: n/(n-1)(n+1)
Expand: n/(n^2-1)</p>
<p>Equate as previously described.
n=5 and n^2-1=k
Substitute: 5^2-1=k
Solve: 24=k</p>
<p>Just cross out one “n” in the numerator and one in the denominator. Then let n = 5.</p>