(-3/7-5/14-8/21)*3/14+5/6=(-18/42-15/42-16/42)*3/14+5/6=-49/42*3/14+5/6=
=-(49*3)/(42*14)+5/6=-1/4+5/6=-3/12+10/12=7/12
(-3/7-5/14-8/21)*3/14+5/6=(-18/42-15/42-16/42)*3/14+5/6=-49/42*3/14+5/6=
=-(49*3)/(42*14)+5/6=-1/4+5/6=-3/12+10/12=7/12