Question

Am nevoie de puțin ajutor daca se poate...

Answer 1

$\it \dfrac{C_{100} ^{50}}{C_{99} ^{50}} =\dfrac{100!}{50!\cdot50!}\cdot\dfrac{50!\cdot49!}{99!}=\dfrac{100}{50}=2 \Rightarrow C_{100} ^{50}=2\cdot C_{99} ^{50}$