What is the 6th term of this geometric sequence?

5, - 15, 45, - 135 ...

Answer:3645 First we have to know the type of this sequenceso it is clear that the sequence is not increasing with a constant value so I think it is geometric sequence and to make sure If we divide

brainliest?

A geometric series has the general formula for calculating the next number as follows

Series is 5, 15, 45, T4, T5, T6

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 so this must be a common ratio all through)

n = the next terms we're to calculate ...

as you already have 1st, 2nd and 3rd terms ... then the next one is 4th then 5th and 6th.

therefore n = 4

substituting now

T4 = ar^n-1

= 5*3^4-1

= 5*3^3

= 5*27

T4 = 135

T5 = ar^n-1

= 5*3^5-1

= 5*3^4

= 5*81

T5 = 405

T6 = ar^n-1

= 5*3^6-1

= 5*3^5

= 5*243

T6 = 1215

Therefore whole series is 5, 15, 45, 135, 405, 1215 withe the last 3 being your required ones.