# Thread: I must be blind, simplication

1. ## I must be blind, simplication

How does this finite sum formula of
$\frac{3(1-\frac{1}{2}^{11})}{1-\frac{1}{2}}$
Get simplified to...

$\frac{3(2^{11}-1)}{2^{10}}$
Its late ....

2. Originally Posted by RockHard

How does this finite sum formula of
$\frac{3(1-\frac{1}{2}^{11})}{1-\frac{1}{2}}$
Get simplified to...

$\frac{3(2^{11}-1)}{2^{10}}$
Its late ....
Simplify denominator: 1 - 1/2 = 1/2. Now multiply numerator and denominator by 2^11.

3. Ok, that make sense, thanks, however, how do you choose what to multiply the the fraction by and why? Sorry for the elementary questions, Ive been up for way to long,

4. Originally Posted by RockHard
Ok, that make sense, thanks, however, how do you choose what to multiply the the fraction by and why? Sorry for the elementary questions, Ive been up for way to long,
Look at what the end result is meant to be. Get some sleep. It's a waste of time asking things that you'd be able to do if you weren't tired.

5. Well what would the reason be if I had not seen the end result?

6. Originally Posted by RockHard
Well what would the reason be if I had not seen the end result?
No reason. The end result is how someone decided they wanted the answer written as. Unless you're told otherwise, the answer can be left in any form you want.