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1 vote
Determine if the sequence below is arithmetic or geometric and determine the

common difference / ratio in simplest form.
5, 15, 45, ...

User AlphaGoku
by
6.5k points

1 Answer

7 votes
a1=5
a2=15
a3=45
a2/a1=15/5=3
a3/a4=45/15=3
Sequence is geometric-the ration of each term and previous term is CONSTANT. Ratio is: 3
There is no common difference (d), as sequins not arithmetic.

d=a(n) - a(n-1)
a(n) is last term
a(n-1) is the previous term
d=45-15
d=30
d=15-5=10
The difference between each number in sequence is not the same therefore, there is not common difference.

Good luck.
User Dvtoever
by
7.5k points
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