Question

сократить дробь (n+1)!/(n+3)!

Answer 1

$\frac{(n+1)!}{(n+3)!}= \frac{1*2*3*...n(n+1)}{1*2*3*...*n(n+1)(n+2)(n+3)}= \frac{1}{(n+2)(n+3)}$