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Ekejessica
a fost răspuns

1 supra 1+√2+1supra√2+√3+1supra √3+√4+....+1supra √n+√n+1 =26 

Răspuns :

Bunicaluiandrei
1/(1 +√2) +1/(√2 +√3) +1/(√3 +√4) +.........+1/[√n +√(n+1)] = 26
1/ (√2+1) +1/(√3+√2) +1/(√4 +√3) +.......+ 1/[√(n+1) +√n] =26
(√2-1)/1 +(√3-√2)/1 +(√4 -√3)/1 +..........+ [√(n+1) -√n]/1 = 26
√(n+1) -1 = 26
n+1 = 27² = 729  n = 728