Compute the sum from k=0 to infinity of (k+1)(x)(1-x)^k. I don't have any ideas about how to start this one, except that perhaps it resembles a geometric series? Also we're supposed to use the power series for 1/x which we know to be (1-x)^k. (That's all I could figure out on my own so far) What I could really use some help with is how to get started, then I should be able to pick it up from there. Thank you SO much for any help!