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What is the sum of the sixth terms of the geometric series 2-6+18-54+

User Elijah M
by
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1 Answer

2 votes

Answer: 122

Explanation:

Since it is a geometric sequence, lets see the pattern below:

  • -6÷2=-3
  • 18÷-6=-3
  • -54÷18=-3

From this, we can see that we multiply each number by -3 to get the next number.

Before we find the sum, we first find the next number.

-54×-3=162

So the whole sequence will be: 2, -6, 18, -54, 162

Find the sum

2+(-6)+18+(-54)+162

=2-6+18-54+162

=-4-36+162

=-40+162

=122

Hope this helps!! :)

Please let me know if you have any question

User Darrell H
by
6.2k points