Question

Exercitiul 24 E URGENTTT

Answer 1

Răspuns:

$\frac{1}{a1} + \frac{1}{a2} - \frac{1}{a2} + \frac{1}{a3} - \frac{1}{a3} + .... \frac{1}{an - 1} - \frac{1}{an} = \frac{n - 1}{a1an}$

$\frac{1}{a1} - \frac{1}{an} = \frac{n - 1}{a1an} \\ \frac{a1 - an}{a1an} = > an = a1 + n - 1 \\ = \frac{n - 1}{a1a \: n}$

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