Question

$\frac{8!}{3!x5!}- \frac{9!}{2!x7!} aratati ca este numar natural$

Answer 1

$\frac{8!}{3!5!} = \frac{6*7*8}{3!(=6)}=7*8=56$
$\frac{9!}{2!7!}= \frac{8*9}{2} =36$
Deci 56-36=20∈N