a) 7/9 = 35/45 5/3 = 25/15 11/15 = 55/75 б) 7/9 = 21/27 5/3 = 15/9 11/15 = 33/45 в) 7/9 = 70/90 5/3 = 50/30 11/15 = 110/150 г) 7/9 = 56/72 5/3 = 40/24 11/15 = 88/120