Question

Сократить дробь: (n+1)!/(n+3)!

Answer 1

$frac{(n+1)!}{(n+3)!}= frac{1cdot 2cdot ...cdot ncdot (n+1)}{1cdot 2cdot ...cdot ncdot (n+1)cdot (n+2)cdot (n+3)} = frac{1}{(n+2)(n+3)}$