<h3>
Answer: 2</h3>
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Explanation:
To get the 6th term, we multiply the fifth term by the common ratio
6th term = (fifth term)*(common ratio)
6th term = 162*3
6th term = 486
The 7th term is found by tripling 486, and so on.
To get the fourth term, we go in reverse of this process. We'll divide 162 by 3 to get 162/3 = 54
The third term is then going to be 54/3 = 18
The second term is 18/3 = 6
The first term is 6/3 = 2
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Here's another way we can solve this question.
The nth term of a geometric sequence is a*(r)^(n-1)
We know that the common ratio is 3, so r = 3.
The 5th term is 162, meaning plugging n = 5 into that expression above leads to 162, so,
a*(r)^(n-1)
a*(3)^(n-1)
a*(3)^(5-1) = 162
a*(3)^4 = 162
a*81 = 162
81a = 162
a = 162/81
a = 2 is the first term
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The first five terms of the geometric sequence are:
2, 6, 18, 54, 162
Each time we go from left to right, we're multiplying by 3. Going in reverse (right to left), we divide by 3.
Multiplying by 1/3 is the same as dividing by 3.
