Решение:
- \( \frac{5}{7} + 0.39 \approx 0.714 + 0.39 = 1.104 \approx 1.10 \)
- \( \frac{11}{12} - 0.54 \approx 0.9167 - 0.54 = 0.3767 \approx 0.38 \)
- \( 8.58 + \frac{8}{15} - \frac{3}{16} \approx 8.58 + 0.5333 - 0.1875 = 8.9258 \approx 8.93 \)
- \( 9.48 - \frac{3}{8} - \frac{4}{5} \approx 9.48 - 0.375 - 0.8 = 8.305 \approx 8.31 \)
Ответ: 1) \( \approx 1.10 \) 2) \( \approx 0.38 \) 3) \( \approx 8.93 \) 4) \( \approx 8.31 \).