Find the common ratio for the following sequence. 27, 9, 3, 1, ... User: Find the common ratio for the following sequence. 1/2,-1/4, 1/8, - 1/16 User: What is the seventh term of a sequence whose first term is 1 and whose common ratio is 3? 243 729 2,187

Question

Marina Dorsey

Mathematics

16 October, 17:11

Find the common ratio for the following sequence. 27, 9, 3, 1, ... User: Find the common ratio for the following sequence. 1/2,-1/4, 1/8, - 1/16 User: What is the seventh term of a sequence whose first term is 1 and whose common ratio is 3? 243 729 2,187

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Answers (1)

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Ann Mcfarland · Answer 1

R=common ratio = an / an-1

27,9,3,1 ...;

r=an/an-1 = a₂/a₁=9/27=1/3

r=1/3.

1/2,-1/4,1/8,-1/16

r=an/an-1 = (-1/4) / (1/2) = - 2/4=-1/2

r=-1/2.

a₁=1

r=3

an=a₁*r^ (n-1)

a₇=1.3⁷⁻¹=3⁶=729

a₇=729