Номер 755 пожалуйста

а)1/2-1/4+2/5 = 10/20 -5/20 + 8/20 = 23/20 = 1 3/20 б) 3/4 -1/2 +7/8 = 6/8- 4/8 +7/8  = 9/8 = 1 1/8 в) 1/3-1/9+1/6 = 6/18 -2/18 +3/18 = 7/18 г) 5/6-2/3+1/4 = 10/12 - 8/12 +3/12 = 5/12