Question

For the arithmetic sequence beginning with the terms (-2, 0, 2, 4, 6, 8...), what is the sum of the first 18 terms?

Answer 1

270

Explanation:

we are making the arithmetic sequence by adding 2 in the previous number to make the next number.

so, the first 18 terms of the arithmetic sequence would be,

-2, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, ....

the sum of the first 18 terms would be = 270