Question

find the sum for the given arithmetic series:

Answer 1

split it up into parts

Answer 2

\[\sum(2-3n)\]
\[\sum2-\sum3n\]
\[2\sum_{5}^{1}-3\sum_{1}^{5} n\]
\[2(5)-3\frac{5(1+5)}{2}\]

Answer 3

lol, i got me 5 and 1 flipped around on that first sum

Answer 4

omg thank you so much! that was some big help right there :)

Answer 5

your so smart lol

Answer 6

yep, another way to look at it, since the index is so small is like this:

2 − 3(1)
2 − 3(2)
2 − 3(3)
2 − 3(4)
2 − 3(5)
-------
2(5) -3(1+2+3+4+5)

Answer 7

oh wow that's much easier for me to understand. thanks

Answer 8

good luck ;)