3/5 = (3*6)/(5*6) = 18/30
5/6 = (5*5)/(6*5) = 25/30
6/11 = (6*9)/(11*9) = 54/99
4/9 = (4*11)/(9*11) = 44/99
5/6 = (5*11)/(6*11) = 55/66
4/11 = (4*6)/(11*6) = 24/66
7/18
1/6 = (1*3)/(6*3) = 3/18
9/13= (9*5)/(13*5) = 45/65
4/5 = (4*13)/(5*13) = 52/65
5/7 = (5*4)/(7*4) = 20/28
3/4 = (3*7)/(4*7) = 21/28
2/15
1/3 = (1*5)/(3*5) = 5/15
5/8
3/4 = (3*2)/(4*2) = 6/8