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Hi!,

 

2^x-2^{x-1}=4

 

I lose the x if i use my 'normal method of immediately 4=2^2 and bringing everything down.

x-(x-1)=2

 Sep 8, 2017
 #1
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\(2^{x}-2^{x-1} =4 \)now factor out  to get

 

\(2^{x-1} (2^{1}- 1)=4\)

 

 

\(2^{x-1}(1) =4\)

\(2^{x-1}=4 \)  since we know that \(2^{2}=4\)

 

then x-1  =2    so x =3.

 

Check  2^3   - 2^2    =   8 - 4     =4

 Sep 8, 2017

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