Tính \(-\frac{5}{10} + \frac{12}{28} + \frac{3}{27} + \frac{7}{18} + \frac{20}{35} =\)

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d) \(-\frac{5}{10} + \frac{12}{28} + \frac{3}{27} + \frac{7}{18} + \frac{20}{35} =\)

c) \(\frac{1}{56} + \frac{1}{72} + \frac{1}{90} + \frac{1}{110} + \frac{1}{132} + \frac{1}{156} =\)

f) \(\frac{4}{21} + \frac{4}{77} + \frac{4}{165} + \frac{4}{285} + \frac{4}{437} + \frac{4}{621} =\)