Answer:
I think the right answer is B.
Answer:6018
Step-by-step explanation:
Given Sequence

It represent an A.P. with
first term 
common difference 
So sum of 51 term
![S_n=\frac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
![S_{51}=\frac{51}{2}\times [2\times (-282)+(51-1)16]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B2%5Ctimes%20%28-282%29%2B%2851-1%2916%5D)
![S_{51}=\frac{51}{2}\times [-564+800]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B-564%2B800%5D)
![S_{51}=\frac{51}{2}\times [236]](https://tex.z-dn.net/?f=S_%7B51%7D%3D%5Cfrac%7B51%7D%7B2%7D%5Ctimes%20%5B236%5D)


Answer:
x=14
Step-by-step explanation:
2 times x = 2x and 2 time 9 is 18 so the equation is 2x-18=10. then you add 18 to both sides and get 2x=28 then simplify to x=14
you can estimate 57.8 and 81 then to check you can do 57.8 divided by 81