7/12:4/5= 5/18:25/27= 3/4:33/20= 9/16:3/64= 25/72:45/63=
7/12 : 4/5 = 7/12 * 5/4 = 35/48 5/18 : 25/27 = 5/18 * 27/25 = 1/6 * 9/5 = 9/30 3/4 : 33/20 = 3/4 * 20/33 = 1 * 5/11 = 5/11 9/16 : 3/64 = 9/16 * 64/3 = 3/1 * 3/1 = 9/1 (9) 25/27 : 45/63 = 25/27 * 63/45 = 5/1 * 7/3 = 35/3 = 11 2/3