+0  
 
+2
1082
4
avatar+1694 

The sum of the first 3 terms of a geometric series is 171 and the common ratio is 2/3.

What is the first term of the series?

 

I Don't know what to do- it says I have to use formula?

 Aug 6, 2019
 #1
avatar+6180 
+2

first off do you know what a geometric series is?

 Aug 6, 2019
 #2
avatar+1694 
+3

Yep!

tommarvoloriddle  Aug 6, 2019
 #3
avatar+6180 
+2

\(\text{well then you should know that the sum of the first three terms are}\\ a + \dfrac 2 3 a + \dfrac 4 9 a = \dfrac{19}{9}a = 171\\ a=81\)

Rom  Aug 6, 2019
 #4
avatar+1694 
0

ok, thank you, Rom!

I got that answer too, I just forgot to post it...

tommarvoloriddle  Aug 6, 2019

30 Online Users

avatar
avatar
avatar
avatar