larkkjavaran
Answered

  1. Is the sequence geometric? If so, identify the common ratio.

6, 12, 24, 48, ...


yes; 2

yes, –2

yes; 4

no


2.What is the fifth term of the geometric sequence?


5, 15, 45, ...


1,215

1,875

405

3,645

Verified Answer :

1) yes;2

62=12
122=24
242=48
2)Next Term (or nth term) = ar^n-1 

a = first term, i.e. 5 
r = common ratio i.e. 3 (as 15/5=3 and 45/15=3 
n = .. 
as you already have 1st , 2nd and 3rd terms
substituting now 
T4= ar^n-1 
= 53^4-1 
= 53^3 
= 527 
T4 = 135 
T5= ar^n-1 
= 53^5-1 
= 53^4 
= 5*81 
T5 = 405 


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