Write out the first three terms and the last term of ∑(-2i+6) (on top of the sigma sign is 40 and on the bottom i=1) . Use the formula for the sum of the first n terms of an arithmetic sequence find the sum.

Question

Write out the first three terms and the last term of ∑(-2i+6) (on top of the sigma sign is 40 and on the bottom i=1) .  Use the formula for the sum of the first n terms of an arithmetic sequence find the sum.

anonymous · Answer

$$\sum_{i=1}^{40}(-2i+6)$$?

kells · Answer

yes thats how the equation looks

anonymous · Answer

first three term
(-2(1)+6)+(-2(2)+6)+(-2(3)+6)

anonymous · Answer

last three term same thing start from 38, 39,40

kells · Answer

thank you I really appreciate the help

anonymous · Answer

Do you need help with arithemtic sum?
Also if I helped you some way, please fan me

kells · Answer

I understand arithmetic sum now thanks to you help but I do need help with another problem.