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Algebra

Please help me .. Write an expression for the term to term formula, this should link Un and Un+1 in the series 2, 6,18,54,162.
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Zacken
22
Original post by Enemma09
Please help me .. Write an expression for the term to term formula, this should link Un and Un+1 in the series 2, 6,18,54,162.


Do you have any thoughts of your own on the matter?

Hint 0: Think about the relation between 2 and 6, and 18 and 6, and 54 and 18.

Hint 1: What number do you multiply 2 by to get 6?

Hint 2: What number do you multiply 6 by to get 18?

Hint 3: What can you tell about how to get from one term in the series to the next term? What do you need to do to the term to get the next?
Reply 2
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Enemma09
OP
I know it's x3. Confused about the Un and Un+1. Didn't do a levels and I am an adult student returning to education after 14 years..
Original post by Enemma09
I know it's x3. Confused about the Un and Un+1. Didn't do a levels and I am an adult student returning to education after 14 years..


UnU_n refers to a general term, and Un+1U_{n+1} refers to the next subsequent term.

So, you're looking for an equation relating the two.

Un+1U_{n+1} as a function of UnU_n

Since you realise it's just multiplying by 3 each time, we get:

Un+1=3UnU_{n+1}= 3U_n

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