# Thread: Finding Simple Expressions....

1. ## Finding Simple Expressions....

Question : Find a simple expression for :

n
Σ k. 2^k . ( n C K )
k=1

2. Originally Posted by aamiri
Question : Find a simple expression for :

n
Σ k. 2^k . ( n C K )
k=1

$f(x)=x\dfrac{d}{dx}(1+x)^n$