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Voicumihaiela
a fost răspuns

1) 1000+1/1000+2/1000+3/1000+...+999/1000
2) 1000-1/1000-2/1000-3/1000-....-999/1000
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Răspuns :

KungfuPanda1
1) 1000+1/1000+2/1000+3/1000+...+999/1000
1000 = 1000*1000/1000

(1+2+...1000)/1000 = (folosind Suma lui Gauss) 1000*1001/2*1000=1001/2=500.5

2) 1000-1/1000-2/1000-3/1000-....-999/1000
=1000 - (1/1000+2/1000+3/1000+...+999/1000) =
=1000 - 999*1000/(2*1000)=1000-999/2=500.5

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