Tìm x, biết: \( 2x + \frac{7}{6} + \frac{13}{12} + \frac{21}{20} + \frac{31}{31} + \frac{43}{42} + \frac{57}{56} + \frac{73}{72} + \frac{91}{90} = 10 \)

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Bài 18. Tìm x, biết: \( 2x + \frac{7}{6} + \frac{13}{12} + \frac{21}{20} + \frac{31}{31} + \frac{43}{42} + \frac{57}{56} + \frac{73}{72} + \frac{91}{90} = 10 \)