Б)4/8=1/2
9/36==1/4
7/28=1/4
5/35=1/7
в)2/8=1/4
8/24=1/3
12/28=3/7
45/100=9/25
г)25/35=5/7
45/54=5/6
8/400=1/50
32/256=1/8
д)12/18=2/3
18/20=9/10
20/24=5/6
24/30=4/5
е)56/49=8/7
40/32=5/4
48/36=4/3
28/21=4/3
ж)21/56=3/8
144/120=6/5
156/128=39/80
396/240=99/80