Answer:
12+2x
Step-by-step explanation:
2(10)+2(x-4)
20+2x-8
12+2x
Answer:1493.1
Step-by-step explanation:
Answer: 432cm^3
Step-by-step explanation:
Answer:

Step-by-step explanation:
The nth term of an arithmetic sequence is given by the formula,

We were given that the 9th term is
.





The sum of the first n-terms is given by the formula,

To find
, we substitute
,
and
.





The correct answer is D