Question

the 1st , 2nd and 3rd terms of a geometric sequence are the 1st 9th and 21st term of an arithmetic sequences

Answer 1

Step-by-step explanation:

1.We'll find the first term in the sequence and write the general rule for the sequence. We will start by using the term we know, the common ratio and the general rule, \begin{align*}a_n=a_1 r^{n-1}\end{align*}. By plugging in the values we know, we can then solve for the first term,

2.the second equation, we get 18r2 = 162.

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