Question

27.
. va roggggg mult !!!​

Answer 1

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Answer 2

Răspuns:

27

Explicație pas cu pas:

a)

$\frac{1}{120} + \frac{2}{120} + \frac{3}{120} + ... + \frac{119}{120} = \frac{1 + 2 + 3 + ... + 119}{120}$

$= \frac{ \frac{119 \times 120}{2} }{120} = \bf \frac{119}{2}$

b)

$\frac{2}{50} + \frac{4}{50} + \frac{6}{50} + ... + \frac{48}{50} = \frac{2 + 4 + 6 + ... + 48}{50} =$

$= \frac{2(1 + 2 + 3 + ... + 24)}{50} = \frac{2 \times \frac{24 \times 25}{2} }{50}$

$= \frac{24 \times 25}{50} = \frac{24}{2} = \bf 12$