Sume de combinari
Posted: Thu Apr 23, 2009 2:45 pm
\(
a) \frac{C_{n}^0}{2}+\frac{C_{n}^1}{3}+.....\frac{C_{n}^n}{n+2}=? \)
\(
b) \frac{C_{n}^0}{1}-\frac{C_{n}^2}{2}+\frac{C_{n}^3}{3}+.....+(-1)^n\frac{C_{n}^n}{n+1}=?
\)
a) \frac{C_{n}^0}{2}+\frac{C_{n}^1}{3}+.....\frac{C_{n}^n}{n+2}=? \)
\(
b) \frac{C_{n}^0}{1}-\frac{C_{n}^2}{2}+\frac{C_{n}^3}{3}+.....+(-1)^n\frac{C_{n}^n}{n+1}=?
\)