Question

Sn=n(n+1) (n+4). and pzz

Answer 1

Hello friend!

Sn = n(n+1) (n+4)
= n square + n ( n + 4)
= n square + n square + 4n
= 2n square + 4n
= 2 ( n square + 2n)
Therfore, Sn = 2 ( n square + 2n)




I hope this helped you. Thank you ^_^

Answer 2

$S_n = n(n+1) (n+4)\\S_n = n^2 + n(n+4)\\S_n = n^2 + n^2 + 5 + 4n\\S_n = 2n^2 + 4n\\S_n = 2(n^2 + 2n)$