Упростите: (n+ 1)!/n! ; (n-1)!/(n+2)!

Question

Упростите: (n+ 1)!/n! ; (n-1)!/(n+2)!

Answer 1

(n+ 1)!/n! = 1*2:...*n*(n+1)/(1*2:...*n) = n+1;
 (n-1)!/(n+2)! = 1*2:...*(n-1)/(1*2:...*(n-1)*)*n*(n+1)*(n+2))=1/(n*(n+1)*(n+2))