Question

Find the sum to n terms of the series whose n^th term is n(n+3)

Answer 1

n(n+3)=n=10=10(10+3)=100+30=130

Answer 2

Answer:

n(n+1)(n+5)/3

Step-by-step explanation:

n(n+3) multiply  n inside

then put ∑

and distribute it

∑n²+3∑n

n(n+1)(2n+1)/6+3(n)(n+1)/2

simplify and get the answer