👤

Aflati sumele: 4+8+12.....+1996= (va rog si sa.mi explicati) plzz

Răspuns :

[tex]\displaystyle 4+8+12+...+1996=4(1+2+3+...+499)=4 \times \frac{499(499+1)}{2} = \\ \\ =4 \times \frac{499 \times 500}{2} =4 \times \frac{249500}{2} =4 \times 124750=499000[/tex]