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Help me
please show your solution ​

Help me please show your solution ​-example-1
User TATN
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2 Answers

3 votes

Answer:


a_(1) = 5

Explanation:

check the attached image for explanation

Help me please show your solution ​-example-1
User Reto Koradi
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3 votes
45 3rd term
135 4th term
405 5th term
1215 sixth term

This a geometric progression
Unknown at leading to equation
For this we need to know the at before knowing the a

Apply general formula
Tn=ar^n-1
T3=360=ar^3-1
360=ar^2.....................(1)

Also,
T6=1215=ar^6-1
1215=ar^5.....................(2)

Divide(2)by(1)

ar^5/ar^2 = 1215/45

By gradual reduction
a can cancel a in ar^5/ar^2
=r^5/r^2
Indices
r^5-2
r^3

1215/45= 27

Therefore, 27=r^3
3^3=r^3
Cube root both side to remove cube
r = 3

To get a the first term
Substitute r in equation 1 to get a

45=a(3)^2
45=a9
45=9a
Divide both side by 9
a=5
User Wrbp
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