Question

Find the sum of the first seven terms of the sequence 4, 12, 36, 108, … .
1,456
1,457
4,372
4,374

Answer 1

Its a GP

Answer 2

what

Answer 3

Okay the easy way I do this is first find the pattern. Do you know what the pattern is?

Answer 4

Common ratio is 3

Answer 5

use S=a(r^n-1)/(r-1)

Answer 6

Yes okay so now do 108*3*3*3

Answer 7

And write down each number that shows when you hit equal

Answer 8

r here is3, a is 4

Answer 9

n is 7

Answer 10

4(3^7-1)/3-1 , we get.................

Answer 11

4372

Answer 12

324, 972, 2916 so you add 4, 12, 36, 108, 324, 972, 2916 together.
We get 4372

Answer 13

got it?

Answer 14

got it?

Answer 15

good job @alexistheking77

Answer 16

thank you so much i appreciate it