The answer to this question is n = 3
Answer:
21 C
22 B
23 169
Step-by-step explanation:
21 3m mean 3 times a certain number
22 the negative make the 4 go negative and the -5 positive
23 i did 5^2-4^2= 9
then 6^2 divided by 9+9= 13 i took the 9 from the 5^2 problem then divided it by 6^2
then 13 x 13 = 169
<u>Answer:</u>
-348
<u>Step-by-step explanation:</u>
We are given the following arithmetic sequence and we are to find the sum of its first 12 terms:
1, -4, -9, -14, . . .
For that, we will use the formula for the sum of the arithmetic mean:

We know the value of the first term (
) but we need to find the value of
. So we will use the following formula:



Substituting these values in the sum formula to get:

-348