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Hello, does anyone know how to solve this? I keep getting it wrong on my homework, thanks!Find the first term of the sequence given by the following~n= 1, 2, 3...an = 5(3)^n-1 I attached an image to this question.

Hello, does anyone know how to solve this? I keep getting it wrong on my homework-example-1

1 Answer

1 vote

Answer:


5,15,45,135

Step-by-step explanation:

Given the nth term of the required sequence expressed according to the equation:


a_n=5(3)^(n-1)

You need to get the first four terms of the sequence as shown:

For the first term, when n = 1


\begin{gathered} a_1=5(3)^(1-1) \\ a_1=5(3)^0 \\ a_1=5(1) \\ a_1=5 \end{gathered}

For the second term, when n = 2


\begin{gathered} a_2=5(3)^(2-1) \\ a_2=5(3)^1 \\ a_2=5(3)_{} \\ a_2=15 \end{gathered}

For the third term, when n = 3


\begin{gathered} a_3=5(3)^(3-1) \\ a_3=5(3)^2 \\ a_3=5(9) \\ a_3=45 \end{gathered}

For the fourth term, when n = 4


\begin{gathered} a_4=5(3)^(4-1) \\ a_4=5(3)^3 \\ a_4=5(27) \\ a_4=135 \end{gathered}

Therefore the first four terms of the sequence will be 5, 15, 45 and 135

User Georgio
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