a) 6/7 - 9/14 = 12/14 - 9/14 = 3/14
б) 9/20 - 5/12 = 18/40 - 25/40 = -7/40
в) 5/9 - 3/8 = 40/72 - 27/72 = 13/72
г) 7/18 - 1/45 = 35/90 - 2/90 = 33/90 = 11/30
a) 6/7 - 9/14 = 12/14 - 9/14 = 3/14
б) 9/20 - 5/12 = 18/40 - 25/40 = -7/40
в) 5/9 - 3/8 = 40/72 - 27/72 = 13/72
г) 7/18 - 1/45 = 35/90 - 2/90 = 33/90 = 11/30