Answer:
e. 1/(49n² +7n)
Step-by-step explanation:
[tex]\dfrac{(7n-1)!}{(7n+1)!}=\dfrac{(7n-1)!}{(7n+1)(7n)(7n-1)!}=\dfrac{1}{(7n+1)(7n)}\\\\=\dfrac{1}{49n^2+7n}[/tex]