Đáp án:
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`A = ( (-4)/5 + 4/3) + ( (-5)/4 + 14/5) - 7/3`
`↔ A = (-4)/5 + 4/3 + (-5)/4 + 14/5 - 7/3`
`↔ A = ( (-4)/5 + 14/5) + (4/3- 7/3) + (-5)/4`
`↔ A = 2 + (-1) + (-5)/4`
`↔A = 1 + (-5)/4`
`↔ A = (-1)/4`
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`B = 8/3 × 2/5 × 3/8 × 10 × 19/92`
`↔ B = (8/3 × 3/8) × (2/5 × 10) × 19/92`
`↔ B = 1 × 4 × 19/92`
`↔ B = 4 × 19/92`
`↔ B = 19/23`
Vậy `B = 19/23`
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`C = (-5)/7 × 2/11 + (-5)/7 × 9/14 + 1 5/7`
`↔ C = (-5)/7 × (2/11 + 9/14) + 12/7`
`↔ C = (-5)/7 × 127/154 + 12/7`
`↔ C = (-635)/1078 + 12/7`
`↔ C = 1213/1078`
Vậy `C = 1213/1078`
