Question

Aratati ca numarul 2+4+6+........+2n nu este patrat perfect

Answer 1

[tex]2+4+6+...+2n = 2(1+2+3+....+n)= 2\frac{(n+1)*n}{2} =
 =(n+1)*n= n^{2} +n \neq patrat perfect [/tex]