Question

Find the sum of the first 12 terms of the sequence.

1, -4, -9, -14, . . .

Answer 1

If you subtract each number from each other, you should get and equal 5 in between each one, so find the summation equation

Answer 2

so your summation notation should be:
\[\sum_{0}^{11}(1-5n)\]

Answer 3

I don't need the summation notation, just the sum.

Answer 4

I got -318 as the sum... I hope that's correct.

Answer 5

yea, that's what I got too