( 1 12\12 - 1 7\12 = 5\12
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3\8 - 1\6 = (18 - 8)\48 = 10\48 = 5\24
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5\12 : 5\24 = 2
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2\1 * 13\4 = 13\2 = 6.5
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ответ: 6.5