Question

VA ROOOG!!! AM NEVOIE DE AJUTOR PENTRU REZOLVAREA PROBLEMEI!!!​

Answer 1

Răspuns:

Explicație pas cu pas:

1/1 ; 1/2 ; 2/2 ; 2/1 ; 1/3 ; 2/3 ; 3/3 ; 3/2 ; 3/1 ; .....1/n;2/n;...n/n ; n/n-1 ; n/n-2 ; ....;n/1

n ∈ N*

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n = 2009 => x fractii = ?

n = 1  => 1 fractie

n = 2 => 3 fractii

n = 3 => 5 fractii

n = 4 => 7 fractii  n = k  => 2k-1 fractii

n = 2019 = 2·2019-1 = 4037 fractii

x = 1+3+5+....+4037 = (1+4037)·2019:2 = 2019² fractii

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n = 1 => 1 = 1² fractii

n = 2 => 1+3 = 4 fractii = 2² fractii

n = 3 => 1+3+5 = 9 fractii =3² fractii

n = k => 1+3+5+..+k = k² fractii

n = (k+1) ====> (k+1)² fractii