Question 814540
Proof:

n! + (n+1)!=
n! + (n+1)*(n)(n-1)(n-2)...=
n! + (n+1)n!=
n![1+(n+1)]=
n!(n+2)



or...


n!(n+2)=
n![(n+1)+1]=
n!*(n+1)+1*n!=
(n+1)!+n!=
n!+(n+1)!