Giúp mik với các bạn ơi.!

`5/10+21/28=1/2+3/4=2/4+3/4=5/4`

`7/9+15/27=7/9+5/9=12/9=4/3`

`16/24-1/3=2/3-1/3=1/3`

`6/7-12/28=6/7-3/7=3/7`

`6/45+20/180=2/15+1/6=4/30+5/30=9/30=3/10`

`150/40+5/25=15/4+1/5=75/20+4/20=79/20`

`210/280-54/108=3/4-1/2=3/4-2/4=1/4`

`5/2005-2/2002=1/401-1/1001=1001/401401-401/401401=600/401401`