Salutare!
Rezolvare: n∈|N, cel mai mic;
S = 1/1*2 + 1/2*3 + ... + 1/9*10 + n/10
S = 2-1/1*2 + 3-2/2*3 + ... + 10-9/9*10 + n/10
S = 2/2 - 1/2 + 3/2*3 - 2/2*3 + ... + 10/9*10 - 9/9*10 + n/10
S = 1 - 1/2 + 1/2 - 1/3 + ... + 1/9 - 1/10 + n/10
S = 1 - 1/10 + n/10
S = 9+n/10