SOLUTION: My book says that the sum of the first 10 terms of the sequence {300,150,75,...} is {{{75(2^10-1)/2^7}}} Why is this? Using the formula {{{ A1(1-r^n)/(1-r) }}} I got {{{3

Algebra ->  Sequences-and-series -> SOLUTION: My book says that the sum of the first 10 terms of the sequence {300,150,75,...} is {{{75(2^10-1)/2^7}}} Why is this? Using the formula {{{ A1(1-r^n)/(1-r) }}} I got {{{3      Log On


   

Question 973329: My book says that the sum of the first 10 terms of the sequence {300,150,75,...} is 75%282%5E10-1%29%2F2%5E7
Why is this? Using the formula ++A1%281-r%5En%29%2F%281-r%29+ I got 300+%281-%281%2F2%29+%5E10%29%2F%281-1%2F2%29
Am I wrong? Or is my answer simply in a different form? If so, please explain how I can arrive at the answer similar to the one found in my book.
Much Thanks.
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Your result seems perfectly consistent with what is found in http://en.wikipedia.org/wiki/Geometric_series, under Sum, Formula section of the article. You can check any typical intermediate algebra book, also.