1525. Найдите неизвестный член пропорции:

Решение:

1. \( \frac{6}{11} = \frac{x}{55} \) \( \Rightarrow x = \frac{6 \times 55}{11} = 6 \times 5 = 30 \).
2. \( \frac{3}{8} = \frac{45}{x} \) \( \Rightarrow x = \frac{8 \times 45}{3} = 8 \times 15 = 120 \).
3. \( \frac{x}{15} = \frac{24}{90} \) \( \Rightarrow x = \frac{15 \times 24}{90} = \frac{360}{90} = 4 \).
4. \( \frac{8}{x} = \frac{104}{117} \) \( \Rightarrow x = \frac{8 \times 117}{104} = \frac{936}{104} = 9 \).
5. \( \frac{x}{19,5} = \frac{2}{3} \) \( \Rightarrow x = \frac{19,5 \times 2}{3} = \frac{39}{3} = 13 \).
6. \( \frac{37,8}{x} = \frac{7}{15} \) \( \Rightarrow x = \frac{37,8 \times 15}{7} = \frac{567}{7} = 81 \).

Ответ: 1) 30; 2) 120; 3) 4; 4) 9; 5) 13; 6) 81.