Răspuns :

Iarina82id
  • Hey:)

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  • Teorema lui Gauss

1+2+3+...+n= n•(n+1):2

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  • Rezolvare:

A= (1+2+3+...+50)-(1+2+3+...+30)

A=[50•(50+1):2]-[30•(30+1):2]

A=1275-465

A=810

B=(1+2+3+...+100)-(50+51 +52+... +100)

B=[100•(100+1):2]-[50•(1+2+3+...+50)]

B=5050-{50•[50•(50+1):2]}

B=5050-50•1275

B=63750

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~Succes~

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★iarina82★

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