Question

Given the sequence –3, 0, 3, which of the following is equivalent to:

Answer 1

\[\sum_{n=5}^{8}A -subscript- N\]

Answer 2

54
102
144
162

Answer 3

@primeralph @terenzreignz

Answer 4

@Zarkon

Answer 5

First term is -3, common difference is 0-(-3) = 3
So, the sequence is \[a_n = -3+3(n-1)\]

Answer 6

so, we can do that plugging n-2, n-3 etc. into the next equations?

Answer 7

[-3+3(n-1)]+[-3+3(n-2)] etc.?

Answer 8

You need to find sum from the fifth term to the eighth term, so, find a5, a6, a7, a8 and add them together.

Answer 9

n is the number of term

Answer 10

that's right we start on 5 right? so like this?

Answer 11

e.g.
\[a_5 = -3+3(5-1)=...\]

Answer 12

Start from 5, yes.

Answer 13

[-3+3(n-5)]+[-3+3(n-6)]+[-3+3(n-7)]+[-3+3(n-8)]?

Answer 14

(-3+3n-15)+(-3+3n-18)+ (-3+3n-21)+ (-3+3n-24)?

Answer 15

am I doing this right?

Answer 16

(3n-18)+(3n-21)+(3n-24)+(3n-x)+(3n-27)

Answer 17

i'm not sure what to do from there

Answer 18

No

Answer 19

\[a_5 = -3+3(5-1)\]\[a_6 = -3+3(6-1)\]\[a_7 = -3+3(7-1)\]...
Then, find \(a_5+a_6+a_7+a_8\)

Answer 20

=−3+3(5−1)

=−3+3(6−1)

=−3+3(7−1)

=-3+3(8-1)

Answer 21

=-6+15 =-6+18 =-6+21 =-6+24
=9 =12 =15 =18
9+12+15+18

Answer 22

54

Answer 23

thank you so much guys