Question

the n th term of ap is an=2n+2 then sn​

Answer 1

Answer:

$S_{n}= n^{2}+3n$

Step-by-step explanation:

$S_{n}=$ ∑ $t_{n}$

     = ∑ (2n+2)

     = ∑ (2n)+∑(2)

     = 2(∑n) + 2(∑1)

     = 2($\frac{n(n+1)}{2}$) + 2(n)

     = n(n+1)+2n

     = $(n^{2}+n )+2n$

$S_{n}= n^{2}+3n$