Răspuns:
[tex] \frac{6}{n} = \frac{18}{15} \\ 18n = 6 \times 15 \\ 18n = 90 \\ n = \frac{90}{18} \\ n = 5[/tex]
[tex] \frac{n - 1}{22} = \frac{2n}{40} \\ 40(n - 1) = 22 \times 2n \\ 40n - 40 = 44n \\ 40n - 44n = 40 \\ - 4n = 40 \\ n = \frac{ - 40} {4} \\ n = - 10[/tex]
