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Is there a simplified equation for doing something like this:

$(1x) + (2x) + (3x) + (4x) + (5x)$

but the number it goes to (the example goes to 5 ) can be variable?

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Yes, it's $\sum_{k=1}^n kx = x\sum_{k=1}^n k = {nx(n+1)\over 2}.$

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    Much more sense to me... Thankyou :)2012-02-16