A) = 4,1/12 + 1,2/12 = 5, 3/12 = 5, 1/4
б) = 2,9/15 + 3, 5/15 = 5, 14/15
в) = 5, 42/75 + 2, 35/75 = 7,77/75 = 8, 2/75
г) = 7, 9/30 - 2, 8/30 = 5,1/30
д) = 4, 15/24 - 2, 8/24 = 2, 7/24
е) = 5, 15/20 - 2,16/20 = 4,35/20 - 2,16/20 = 2,19/20
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1) 8,3/4 + 7,1/8 = 8,6/8 + 7,1/8 = 15,7/8
2) 25,1/5 - 15,7/8 = 25,8/40 - 15,35/40 = 24,48/40 - 15,35/40 = 9,13/40
ответ: 9,13/40