15/20=18/24, т.к. 15/20=3/4=6/8, 18/24=6/8
20/35<</span>16/25, т.к. 20/35=4/7=28/175, 16/25=112/175
12/30>15/25, т.к. 12/30=4/10, 15/25=3/5=6/10
18/22=27/33, т.к. 18/22=9/11, 27/33=9/11
30/48<36/56, т.к. 30/48=5/8=35/56<br>
ж-не видно
121/77<45/21, т.к. 121/77=11/7, 45/21=15/7<br>
49/63>34/85, т.к. 49/63=7/9=595/765, 34,85=306/765