3 5/8 + 1 2/3 = 3 15/24 + 1 16/24 = 4 31/24 = 5 7/24
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4 4/9 - 2 5/6 = 4 8/18 - 2 15/18 = 3 26/18 - 2 15/18 = 1 11/18
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6 7/12 + ( 5 3/40 - 4 8/15 ) = 6 70/120 + 5 9/120 - 4 64/120 = 11 79/120 - 4 64/120 =
= 7 15/120 = 7 1/8