Question

Stabiliti daca 1+2+3+4+.......+10 se divide cu 5

Answer 1

Aplic formula:

1+2+....+n = $\frac{n*(n+1)}{2}$

In cazul de fata n = 10

Suma 1+2+3+4+.......+10  = $\frac{10*11}{2} = 55$

55 : 5 = 11 rest 0

Da , se imparte la 5 (este multiplu de 5)

Answer 2

1 + 2 + 3 + 4 + .....+ 10 = (1 + 10) * 10/2 = 11 * 5 = 55
55 = 5 SI 11
55 SE DIVIDE LA 5