найдите те дроби которые равны 2/5
4/15,_6/15,_9/21,_12/21
15/28,_12/28.

супер

2/5=4/10=6/15=8/20.... 4/15=8/30=12/45=16/60... 6/15=12/30=18/45=24/60... 9/21=18/42=27/63=36/84 ... 12/21=24/42=36/63=48/84... 15/28=30/56=45/84=60/102... 12/28=24/56=36/84=48/102....