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5 votes
Hello, what’s the answer for number 11? I need help solving it

Hello, what’s the answer for number 11? I need help solving it-example-1
User Jordan Lev
by
6.3k points

1 Answer

3 votes

First, we need to find the common ratio of this geometric sequence.

To do so, let's divide one term by the term before:


r=(30)/(-5)=-6

Now, to find the 8th term of the sequence, let's use the explicit formula below, with the first term a1 = -5 the common ratio r = -6 and n = 8:


\begin{gathered} a_n=a_1\cdot r^(n-1)\\ \\ a_8=-5\cdot(-6)^7\\ \\ a_8=-5\cdot(-279936)\\ \\ a_8=1,399,680 \end{gathered}

Therefore the correct option is the first one.

User Sahibjot Singh
by
6.2k points
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