PLEASE HELP ME POINTS PLEASE HELP!!!!

The following is a geometric sequence.
1, 5, -25, 125,…
TRUE
FALSE

The following is a geometric sequence.
1, -2, 4, -8, 16,…
TRUE
FALSE

The next three terms of the sequence 20, 40, 80, 160,… are 320, 640, and 1280.
TRUE
FALSE

What is the r value of the following geometric sequence?
40, 20, 10, 5,…
one-third
one-half
2
3

Find two geometric means between 4 and 13.5.
6, 9
7, 11
8, 12
9, 14

Find the 7th term of a geometric sequence with t1=5 and r = -2.
300
320
340
360

Find the sum of the geometric sequence 4, 16, 64, 256, 1024.
1045
1176
1256
1364

Find the sum of the geometric sequence 3, 6, 12, 24.
40
42
45
50

Find the sum of the following infinite geometric series, if it exists.
2 + 1.5 + 1.125 + 0.84375 +…
Does not exist
8
10
12

Find the sum of the following infinite geometric series, if it exists. 1/3 + 1/9 + 1/27 +1/81+..
Does not exist
one-fourth
one-third
one-half

1. False

2. True

3. True

4. one-half

5. 7/11 (can't confirm)

6. 320

7. 1024

8. 42 (can't confirm)

9. Doesn't Exist (can't confirm)

10. one-third

Hope these answers help you with what you are doing.

Answer Link

texaschic101 texaschic101 · Answer 2 · 2018-02-14T18:42:03+01:00

1. false
2. true
3. true
4. r = 1/2
5. dont know
6.a(7) = t1 * r^(n - 1)
a(7) = 5 * -2^(7 - 1)
a(7) = 5 * (-2^6)
a(7) = 5 * 64
a(7) = 320 <==
7. s = a(1 - r^n / 1 - r)
s = 4(1 - 4^5 / 1 - 4)
s = 4(1 - 1024 / -3)
s = 4(-1023 / -3)
s = 4(341)
s = 1364 <== or u could have just added ur numbers
8. 3 + 6 + 12 + 24 = 45....because they just wanted the sum of the first four terms...and their is only 4 terms...so just add them.

I do not know the last 2...sorry