Simplify (n!)/((n+1)!)-((n-1)!)/(n!)n!(n+1)!โˆ’(nโˆ’1)!n!?

1 Answer
Nov 30, 2017

1/(n^2-n)1n2โˆ’n

Explanation:

What is n!n! ( nn factorial ) ?

n! =1xx2xx3xx...xxn

So,

(n!)/((n+1)!)-((n-1)!)/(n!)
=cancel(1xx2xx...xxn)/(cancel(1xx2xx...xxn)xx(n+1))-cancel(1xx2xx...xx(n-1))/(cancel(1xx2xx...xx(n-1))xxn)
=1/(n+1)-1/n
=(n-(n+1))/((n+1)(n))
=-1/(n^2+n)