Question

calculati suma numerelor naturale aflate intre 9,(23) si 451/12

Answer 1

Explicație pas cu pas:

$\frac{451}{12} = 37.58(3)$

$9.(23) < n < 37.58(3)$

n ∈ N => n ∈ {10; 11; ...; 37}

$= > S_{n} = 10 + ... + 37 = \\ = (1 + 2 + ... + 37) - (1 + 2 + ... + 9) \\ = \frac{37 \times 38}{2} - \frac{9 \times 10}{2} = 703 - 45 = 658$