Question

what is the sum of the arithmetic sequence 3,9,15, if there are 36 terms

Answer 1

You should have a formula for finding this sum.
n is the number of terms, so for this problem n=36.
d is the common difference. It can be found by subtracting the second term minus the first.

Answer 2

i no its 6

Answer 3

u didn't try the formula i posted in ur previous post?

Answer 4

i guess not

Answer 5

Then the formula to use is
\[(n/2) * [2a_{1} + (n-1)*d]\]

Answer 6

y?just use the formula n u will get the sum, it needs simple airthmetics using a calculator

Answer 7

yes stacey is right

Answer 8

\[a_{1} =3\] since 3 is the first term.

Answer 9

i got 151

Answer 10

sorry wrong post

Answer 11

i believe the answer is 4234

Answer 12

That seems too big.

Answer 13

3468

Answer 14

3888

Answer 15

n/2 = 36/2 = 18
so we have
18*[2*3 + (36-1) * 6]

Answer 16

are either of those answers right

Answer 17

3888 is correct.

Answer 18

3468 or 3888