# Sum of series

Determine the 6-th member and the sum of a geometric series:

5-4/1+16/5-64/25+256/125-1024/625+....

a6 =  -1.64
SUM =  2.78

### Step-by-step explanation:

$S=\frac{{a}_{1}}{1-q}=\frac{25}{9}=2.78$ Did you find an error or inaccuracy? Feel free to write us. Thank you! Tips to related online calculators
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