# Complicated algebra terms

• November 4th 2009, 10:55 AM
TweedyTL
Complicated algebra terms
This is a little complicated, i'll try to explain as best i can.

Say I have n different numbers, $z\sb{1}, z\sb{2}, ... , z\sb{n}$
I wish to find the summation of every possible way of multiplying $x$ different numbers together.

For clarification: if $n=3, x=2$ I would want:
$z\sb{1}z\sb{2} + z\sb{1}z\sb{3} + z\sb{2}z\sb{3}$
If $n=4, x=3$ i would want:
$z\sb{1}z\sb{2}z\sb{3} + z\sb{1}z\sb{2}z\sb{4} + z\sb{1}z\sb{3}z\sb{4} + z\sb{2}z\sb{3}z\sb{4}$

Basically, I just need a function $F(x,z\sb{1},z\sb{2}, ... ,z\sb{n})$ that gives this result.
• November 4th 2009, 05:28 PM
wonderboy1953