Answer:
= .
Step-by-step explanation:
Given : geometric sequence: 3, –6, 12, –24.
To find : Find s8 for the following geometric .
Solution : We have given geometric sequence: 3, –6, 12, –24.
Where, first term = 3, common ration : = -2.
Formula used :
Where, a = first term , r = common ratio.
= .
= .
= .
= .
= .
Therefore, = .