Question

Which represents the sum of series:
39

40

14

7

Answer 1

have you plugged in values of 1 to 6 to get each value and then just add them up?

Answer 2

:O
its simple lol
u can do it in two ways
1_ plugged values hehe
2_ use the summations rules

so
sum(-3k +4)= -3 (sum k) + 3k
sum k =k(k+1) / 2

sum(-3k +4)= -3 (k(k+1) / 2) + 3k

:3

Answer 3

wait i made a typo
sum(-3k +4)= -3 (sum k) + 4k
sum k =k(k+1) / 2
sum(-3k +4)= -3 (k(k+1) / 2) + 4k

Answer 4

\[\sum _{k=1}^6 (4-3 k)=-39 \]