I know "!" means e.g. 5!=5x4x3x2x1 but how about [3(n+1)!]/[5n!]?
Can you see how n! = n(n-1)!?
or that (n+1)! = (n+1)n! ?
just like 8! = 8(7!)
then [3(n+1)!]/[5n!]
=3(n+1)n! / 5n!
=3(n+1)/5
Can you see how n! = n(n-1)!?
or that (n+1)! = (n+1)n! ?
just like 8! = 8(7!)
then [3(n+1)!]/[5n!]
=3(n+1)n! / 5n!
=3(n+1)/5