-5/8 + (-7/8) = -(5/8 + 7/8 ) = -12/8 = - 1 4/8 = -1 1/4
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1 2/7 + 3/14 = 1 4/14 + 3/14 = 1 7/14 = 1 /12
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-2 5/6 + (-1/6) = -(2 5/6 + 1/6) = -2 6/6 = -3
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-3 7/12 + (-5/24) = -(3 7/12 + 5/24)= -(3 14/24 + 5/24) = - 3 19/24