4,6:(одна целая - три вторых)+одна целая три восьмых
4,6 : (1 2/3 - 3,2) + 1 3/8 = -1 5/8, 1) 1 2/3 - 3,2 = 5/3 - 32/10 = 50/30 - 96/30 = -46/30 = -23/15 = -1 8/15, 2) 4,6 : (-1 8/15) = -46/10 : 23/15 = -46/10 * 15/23 = -3, 3) -3 + 1 3/8 = -24/8 + 11/8 = -13/8 = -1 5/8