Answer:
0
Step-by-step explanation:
The formula gives you a relation between S and n. For every n, you can perform the calculation and obtain an S.
So, for n=0 we get 0/2 (0+1) which equals 0. So (0,0) is an (n,S) pair.
I believe the answer is 4
Hi there! :)

4x + 5x + 12 = 6(x - 2)
Combine like terms and distribute the coefficient outside of the parenthesis:
9x + 12 = 6(x) + 6(-2)
9x + 12 = 6x - 12
Subtract 6x from both sides:
9x - 6x + 12 = 6x - 6x - 12
3x + 12 = -12
Subtract 12 from both sides:
3x + 12 - 12 = -12 - 12
3x = -24
Divide both sides by 3:
3x/3 = -24/3
x = -8.
Lets plug in the answer choices and see which one works
A. x = -6
| -6 | < 3
6 < 3
False, so A is not the answer
B. x = -5
| -5 | < 3
5 < 3
False, so B isn't the answer
C. x = -1
| -1 | < 3
1 < 3
True, so C is the answer.
But lets just check D to make sure C is the answer.
D. x = 2
| 2 | < 3
2 < 3
False, so D isn't the answer either.
C is your answer :)