Вычислите а)3/4+1/6 ; б)-8/15-2/3 в)7/12-5/8  г)-1/3+5/6

а) 3/4+1/6 = 9/12+2/12 = 11/12б) -8/15-2/3 = -8/15-10/15 = -18/15 = -1 целая и 3/15 = -1 целая и 1/5 = -1,2в) 7/12-5/8 = 14/24-15/24 = -1/24г) -1/3+5/6 = -2/6+5/6 = 3/6 = 1/2 = 0,5