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I need help solving thisIt’s from my prep guideI will add two additional pictures with the answer options

I need help solving thisIt’s from my prep guideI will add two additional pictures-example-1
User Swenedo
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The formula for a general term in a geometric sequence is given by


a_n=a_1r^(n-1)

The first term of our sequence is 16, then, our geometric sequence would be


a_n=16r^(n-1)

Using the following terms, there's no r that fits for all terms, therefore, this sequence is not geometric.

The general term in a arithmetic sequence is


a_n=a_1+(n-1)d

Where d is the common ratio.

Again, the first term is 16. Using the second term, we can find the value for d.


\begin{gathered} a_n=16+(n-1)d \\ a_2=(15)/(2)\Rightarrow d=(15)/(2)-16=-(17)/(2) \end{gathered}

This arithmetic sequence is


a_n=16-(17)/(2)(n-1)

If we evaluate bigger values for n to check with the other given terms, we have a match.


\begin{gathered} a_3=16-(17)/(2)(3-1)=16-17=-1 \\ a_4=16-(17)/(2)(4-1)=(32)/(2)-(51)/(2)=-(19)/(2) \end{gathered}

Thus, this series converge because it is arithmetic.

User Renato Dinhani
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