1. ## quick simplifying question

Hi, I am trying to simplify 1-2^(n+1)+2^n, I know the answer is 1-2^n but im not sure how they got there? Can someone please help me out.
thank you

2. Hello,

$2^{n+1}=2*2^n$

So factorise by $2^n$

$1-2^{n+1}+2^n=1-2*2^n+2^n=1+2^n(1-2)=1+2^n*(-1)=1-2^n$