Question

did i get the correct answer?

Answer 1

What is the sum of a 30-term arithmetic sequence where the first term is 73 and the last term is -101?

i got the answer:

-392

??

Answer 2

i guess not ..
to find the sum you have to [(a1 + an) / 2] * n

Answer 3

-101-73 = 174 and the terms are -6 apart..

Answer 4

174/29

Answer 5

in your case a1 =73 , an = -101 , n = 30

Answer 6

Coolsector got thiss

Answer 7

now i'm getting -448

Answer 8

i got -420 ..
lets do this together ..
a1 =73 , an = -101 , n = 30
plugging it into [(a1 + an) / 2] * n
we get :
[(-101 + 73 ) / 2] * 30 = (-28 / 2) * 30 = -420

Answer 9

oh that makes sense. thank you!

Answer 10

yw