Question

What is the sum of the geometric sequence 1, 4, 16, if there are 8 terms? (1 points)

21,845

42,372

55,987

87,381

Answer 1

it is each previous number times 4
1 4 16 64 256 1024 4096 16384
add these up and you will have your answer

Answer 2

It Gives Me 21845

Answer 3

S = 1 + 4 + 16 +........8 terms
or, S = 4^0 + 4^1 + 4^2 + ............+4^7 .......(i)
or,4 S = 4^1 + 4^2 +.............+4^7 + 4^8 .......(II)
Subtract i from ii:
3S = 4^8 - 4^0
or S = (4^8 -1)/3

Answer 4

21845 is the right answer

Answer 5

Can U Check One For Me , I Did It
What is the sum of the geometric sequence 1, -4, 16, if there are 7 terms? (1 points)

-5,461

5,461

-3,277

3,277
I Got 3277

Answer 6

@atlas @cbobo

Answer 7

The general formula for a geometric sequence is S = a(r^n -1)/(r-1)
where a is the first term and r the common ratio

Answer 8

so its -3277 , @atlas