Question

4+8+12+...+2000 metoda gauss

Answer 1

$\displaystyle 4+8+12+...+2000=4(1+2+3+...+500)=4 \times \frac{500(500+1)}{2} = \\ \\ =4 \times \frac{500 \times 501}{2} =4 \times \frac{250500}{2} =4 \times 125250=501000$

Answer 2

4+ 8+ 12+ ...+2 000=
4·1+4·2+4·3+ ... +4·500=
4·(1+ 2+ 3+ ...+ 500)=
4·500·501:2=
2·500·501=
1 000·501=
501 000