№ 1
а) - 1/5 - 2/5 = - 3/5
б) 5/7 - 4/7 = 1/7
в) - 7/9 - (- 8/9) = - 7/9 + 8/9 = 1/9
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№2
а) 1/16 - 3/4 = 1/16 - 12/16 = - 11/16
б) - 2/3 - (- 1/2) = - 2/3 + 1/2 = - 4/6 + 3/6 = - 1/6
в) - 5/18 - (- 1/24) = - 5/18 + 1/24 = - 20/72 + 3/72 = - 17/72
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№ 3
11/48 - 9/16 = 11/48 - 27/48 = - 16/48 = - 1/3