8/11 • 11/13 = 8/12
5/18 • 7/10 = 7/9
7 1/2 • 1 1/25 = 15/2 • 26/25 = 39/5 = 7 4/5
1 1/4 • 2 4/5 = 5/4 • 14/5 = 7/2 = 3 1/2
12 1/3 • 3 3/5 = 37/3 • 18/5 = 37•6/5 = 44 2/5
1 1/4 : 1 2/3 = 5/4 : 5/3 = 5/4 • 3/5 = 3/4
7 1/3 : 1 2/9 = 22/3 : 11/9 = 22/3 • 9/11 = 6
6 2/3 : 2 4/7 = 20/3 : 18/7 = 20/3 • 7/18 =
= 140/36 = 35/9 = 3 8/9
2 - 7/8 • 1 1/7 = 2 - 7/8 • 8/7 = 2 - 1 = 1
(1 2/3 + 2 1/6) : 5/6 = (5/3 + 13/6) : 5/6 =
= (10/6 + 13/6) : 5/6 = 23/6 • 6/5 = 23/5 = 4 3/5