Problem

Find the indicated term for the geometric sequence.
$\frac{-5}{243}, \frac{5}{81}, \frac{-5}{27}, \ldots ;$ the 8 th term

Answer

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Answer

\(\boxed{45}\) is the 8th term of the geometric sequence.

Steps

Step 1 :Identify the first term (\(a_1\)) of the geometric sequence, which is \(-\frac{5}{243}\) or approximately -0.0205761316872428.

Step 2 :Find the common ratio (\(r\)) by dividing any term by the previous term. In this case, \(r = -3.0\).

Step 3 :Identify the term number (\(n\)) that we want to find, which is 8.

Step 4 :Use the formula for the nth term of a geometric sequence, \(a_n = a_1 * r^{(n-1)}\), where \(a_n\) is the nth term, \(a_1\) is the first term, \(r\) is the common ratio, and \(n\) is the term number.

Step 5 :Substitute the values into the formula: \(a_8 = -\frac{5}{243} * (-3)^{8-1}\).

Step 6 :Simplify the expression to get the 8th term of the geometric sequence, which is 45.

Step 7 :\(\boxed{45}\) is the 8th term of the geometric sequence.

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