3/8-2/7+5/8-5/7;11/14-7/100-21/100-13/14;-12/19-15/26+3/19+9/19;2/7-5/9-4/9-4/7

3/8-2/7+5/8-5/7=3/8+5/8-2/7-5/7=8/8-7/7=1-1=011/14-7/100-21/100-3/14=11/14-3/14-7/100-21/100=8/14-28/100=4/7-7/25=100/175-49/175=51/175-12/19-15/26+3/19+9/19=-15/262/7-5/9-4/9-4/7=2/7-4/7-5/9-4/9=-2/7-9/9=-2/7-1=-1 2/7