Determine whether the serie is convergent or divergent , if it is convergent find its sum.
Ʃ∞n=1 (1 + 2n )/ 3n
Ʃa(r)n-1 = a / (1-r) r < 1 is converging or if r > 1 diverging
The Attempt at a Solution
Well I can see its a geometric series so i did Ʃ (1/3)^n + (2/3)^n and r < 1 therefore its convergent but I can't figure out the a. I thought it would be one but the answer key says 1/3 and 2/3 as the a for both series