Answer:
1/7
Explanation:
Given series :-
- 1/5 -2/25 +4/125 - 8/625 ( correct)
To find :-
- The sum of infínite Series .
From the Series , the common ratio will be ,
⇝ CR = -2/25 ÷ 1/5
⇝ CR = -2/25 × 5
⇝ CR = -2/5
Using formula of GP :-
⇝ S_∞ = a /1 - r , -1 < r < 1
⇝ S = 1/5 ÷ ( 1 - (-2/5))
⇝ S = 1/5 ÷ ( 1 +2/5)
⇝ S = 1/5 ÷ 5/7
⇝ S= 1/7