The order of 1- 1/2 to the nth power a= 1/2+ 1/2? + 1/2? +...+1/2 multiplied by 2 on both sides.

2a= 1+ 1/2+ 1/2？ + 1/2? +...+ 1/2 N- 1 power

minus

On the left is 2a-a = a.

Yes, the middle 1/2+ 1/2? + 1/2? The N- 1 power of+...+12 is the same, so the subtraction will cancel it out.

So on the right is 1- 1/2 2009.

So 1/2+ 1/2? + 1/2? The n power of +...+ 1/2 = the n power of1-1/2.