The following expansion can be written in two ways.
Note the placement of the exponents in the equivalent sums.
I dont know how to do the signals so ill right in words everything....
(1-1)^n = n SIGMA k=0 nCk * 1^k *(-1)^(n-k)
why does it equals to:
n SIGMA k=0 nCk * (-1)^k
i dont understand why (-1)^(n-k) become (-1)^k
someone can help me please???