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anonymous
 one year ago
Find the sum of the geometric sequence –3, 15, –75, 375, … when there are 8 terms and select the correct answer below.
anonymous
 one year ago
Find the sum of the geometric sequence –3, 15, –75, 375, … when there are 8 terms and select the correct answer below.

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SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1\(\large\color{black}{ \displaystyle {\rm S}_{\rm n}=\frac{a_1\times \left(1{\rm r}^{\rm n}\right)}{1{\rm r}} }\) this is the formula, for the sum of a geometric sequence that starts from some \(a_1\) and has n terms.

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1you need to find r, identify the \(a_1\) that you are given, and tell me the number of terms (which you plug in for n). plug everything into the formula, and calculate.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I think I did something wrong in the equation because I got 24,414,063

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1holly molly.....

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1yeah it is wrong

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1tell me what was your common ratio (r)? what was your number of terms? what is the first term?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0My common ratio was 5 The number of terms was 8 The first term was 3

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\((1(r^n))\) is what I meant

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1\(\large\color{black}{ \displaystyle {\rm S}_8=\frac{ (3)\times \left(1(5)^8\right)}{1(5)} }\) Click \(\bf\color{blue }{\href{http:///www.wolframalpha.com/input/?i=%283+%C3%97+%281++%285%29%5E8%29%29%2F%281%285%29%29}{here}}\) to check the result.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0My common ratio was 5 The number of terms was 8 The first term was 3

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is the answer 195,312??

SolomonZelman
 one year ago
Best ResponseYou've already chosen the best response.1yes, that is the answer.
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