Salut,
Știm formula (o știai ?):
[tex]C_n^k=\dfrac{n!}{k!\cdot (n-k)!}.\\\\C_5^5=\dfrac{5!}{5!\cdot (5-5)!}=\dfrac{5!}{5!\cdot 0!}=1,\ am\ folosit\ c\breve{a}\ 0!=1.[/tex]
Green eyes.
