Question

What is the sum of the first 35 consecutive odd numbers? Do i Multiply with this

Answer 1

will it be 1225?

Answer 2

what class is this for?

Answer 3

\(\sum_1^{35}(2n-1)\)

Answer 4

Math 104

Answer 5

\(\sum_1^{35}(2n-1)=\sum_1^{35}2n-\sum_1^{35}1=2\sum_1^{35}n-35=2(630)-35=1225\)

Answer 6

what is math 104?

Answer 7

note: \(\sum_1^kn=\frac{k(k+1)}{2}\)

Answer 8

ok thanks and I do this with the rest of my problems like this?

Answer 9

no idea.

Answer 10

all I really used was that last thing.

Answer 11

\(\sum_1^kn=\frac{k(k+1)}{2}\)

Answer 12

if you want to know why, look at example of summing up

1 - 20

take them and write them out like this

1 + 2 + 3 + 4 +5 + 6 + 7 + 8 + 9+10
+20+19+18+17+16+15+14+13+12+11
now if we add each column up and down we get
21+21+21+21+21+21+21+21+21+21
=10(21)=(20*21)/2

Answer 13

tis just an arithmetic sequence
all odd numbers up to 35

1, 3, 5, 7 ....

then you find the "common difference" and then get the partial sum of them

Answer 14

as zzr0ck3r showed above, using the \(\Large \Sigma\) notation

Answer 15

ok thx