Tính hợp lý
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Bài 3. Tính hợp lý:
a) \( \frac{27}{13} + \frac{9}{7} + \frac{12}{13} + \frac{9}{7} \)
b) \( \frac{8}{15} - \frac{4}{9} + \frac{8}{15} - \frac{9}{5} - 3 \cdot \frac{2}{5} \)
c) \( \frac{5}{7} \cdot \left( \frac{15}{8} - \frac{1}{4} \right) - \frac{5}{7} \cdot \left( \frac{1}{4} + \frac{1}{2} \right) \)
Bài 3. Tính hợp lý:
a) \( \frac{27}{13} + \frac{9}{7} + \frac{12}{13} + \frac{9}{7} \)
b) \( \frac{8}{15} - \frac{4}{9} + \frac{8}{15} - \frac{9}{5} - 3 \cdot \frac{2}{5} \)
c) \( \frac{5}{7} \cdot \left( \frac{15}{8} - \frac{1}{4} \right) - \frac{5}{7} \cdot \left( \frac{1}{4} + \frac{1}{2} \right) \)