Find the sum of ∑n=1∞3n(n+3)\sum_{n=1}^{\infty} \frac{3}{n(n+3)}∑n=1∞n(n+3)3.
111
1+1/2+1/31 + 1/2 + 1/31+1/2+1/3
1/31/31/3
333