👤

5×1+5×2+5×3+....+5×51 de rezolvat

Răspuns :

Folosim suma lui Gauss

1+2+3+.....+n=[n(n+1)]/2

5×1+5×2+5×3+....+5×51 =

5×(1+2+3+...+51) =

5×[51×(51+1)]/2 =

13260/2 = 6630