Question

I have two problems that I need some help with. I believe I got to the answer but not quite sure if its right. I need to expand and evaluate each series.

1. There is an E like symbol that has a 7 at the top. On the bottom k=1 and on the right side (-1)^k K
2. There is an E like symbol that has a 8 at the top. ON the bottom K=3 and on the right side (-1)K/K(k-2)

Answer 1

∑ (capital sigma) = "the sum of" whatever follows.

The bottom number indicates where you start the sum, while the top indicates the end.

http://en.wikipedia.org/wiki/List_of_mathematical_symbols

Go down 3/4 of the way to the ∑ symbol.

Answer 2

I think you are describing sigma notation
∑ (-1)^k k from k-1 to 7
= (-1)^1 (1) + (-1)^2 (2) + (-1)^3 (3) + .... + (-1)^7 (7)
= -1 + 2 - 3 + 4 - ... -7
= -4

In the second I can't tell where the denominator ends
is it (-1)^ k /( (k(k-2)) ?
brackets are essential here
once you have decided on the proper meaning,
sub in k=3, 4, ..., 8 adding the resulting terms.