Вопрос:

40. Сократите: 1) \(\frac{9 \cdot 16}{8 \cdot 27}\); 2) \(\frac{8 \cdot 28}{35 \cdot 12}\); 3) \(\frac{2 \cdot 3 \cdot 5}{4 \cdot 9 \cdot 25}\); 4) \(\frac{7 \cdot 13 - 7 \cdot 2}{35 \cdot 9 + 35 \cdot 2}\).

Ответ:

  1. \(\frac{9 \cdot 16}{8 \cdot 27}=\frac{3^2 \cdot 2^4}{2^3 \cdot 3^3}=\frac{2}{3}\).
  2. \(\frac{8 \cdot 28}{35 \cdot 12}=\frac{2^3 \cdot 2^2 \cdot 7}{5 \cdot 7 \cdot 2^2 \cdot 3}=\frac{8}{15}\).
  3. \(\frac{2 \cdot 3 \cdot 5}{4 \cdot 9 \cdot 25}=\frac{2 \cdot 3 \cdot 5}{2^2 \cdot 3^2 \cdot 5^2}=\frac{1}{30}\).
  4. \(\frac{7 \cdot 13-7 \cdot 2}{35 \cdot 9+35 \cdot 2}=\frac{7(13-2)}{35(9+2)}=\frac{7 \cdot 11}{35 \cdot 11}=\frac{1}{5}\).

Ответ: 1) \(\frac{2}{3}\); 2) \(\frac{8}{15}\); 3) \(\frac{1}{30}\); 4) \(\frac{1}{5}\).