Răspunsuri

2014-10-10T10:42:22+03:00
1+2+3+4+...+100=
=(100*101):3=
=10100:3=
=3366,6      
Rezolva-le si tu pe restul dupa model
*= inmultit
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Cel mai inteligent răspuns!
2014-10-10T10:48:27+03:00
1+2+3+4+........+100=100*101/2=5050aplicam 1+2+3+++..++n=n*(n+1)/2

2+4+6+8+.......+100=2*(1+2+3+...+50)=2*50*51/2=2550
1+3+5+....+2013=1+3+5+..+(2*1006+1)=(1006+1)²=1007²

aplic formula 1+3+5+..+2n+1=(n+1)²

(2+4+6+....+4206)-(1+3+5+....+2013)=2*50*51/2--1007²=2550-1007²



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