a) n!/(n-1)!=(n*(n-1)!)/ (n-1)!=n;
б) (2k+1)!/(2k-1)!=(2k+1)*2k*(2k-1)!/(2k-1)!= (2k+1)*2k=4k^2+2k;
в) n!/2!*(n-2)! = (n*(n-1)* (n-2)!)/ (2!*(n-2)!)= n*(n-1)/2;
г)(4m-1)!/(4m-3)!= ((4m-1)*(4m-2)* (4m-3)!)/(4m-3)!= (4m-1)*(4m-2)=
=16m^2-12 m +2;
a) n!/(n-1)!=(n*(n-1)!)/ (n-1)!=n;
б) (2k+1)!/(2k-1)!=(2k+1)*2k*(2k-1)!/(2k-1)!= (2k+1)*2k=4k^2+2k;
в) n!/2!*(n-2)! = (n*(n-1)* (n-2)!)/ (2!*(n-2)!)= n*(n-1)/2;
г)(4m-1)!/(4m-3)!= ((4m-1)*(4m-2)* (4m-3)!)/(4m-3)!= (4m-1)*(4m-2)=
=16m^2-12 m +2;